Watched some of your clips and have some present and future advice, its general advice for beginners as well I guess:
Build beds asap, always do this on a new fort. Sleeping outside without beds is bad. Having a collection of beds perhaps nine in a corner for dwarves without a room is adequate until you have built a room for them. Just desigante the beds as a dormitory and they will sleep there freely. It will give less of a bad thought.
Also deconstruct that wagon for few wood and designate your big dining hall as a meeting hall. The dwarves and any cats/dogs will gather there instead of outside.
When you get migrants you probably
want to control that none of them is a vampire right away. Its troublesome and currently somewhat rare, but it does pay off. Specially since once you have a 120 fort it might well take 20-30 minutes or more just to read all the descriptions on dwarves and think about how likely it is each dwarf is a vampire. Plus it has probably killed once or twice already if you didnt catch it coming in. Save for savescumming you wont get those perhaps skilled dwarves back.
Golden rule:
Everything that can be made out of stone should be made out of stone and nothing else. Ex: Its very easy to make furniture and barrels out of wood but this should be avoided. Stone is abundant, wood is needed for much when the metalworking starts.
Have a central staircase and every time you mine and do something do it on a separate level. Do not add stuff on the same levels. This reduces the steps each dwarf have to take in order to get to stuff since going up/down one level only takes a step, but walking along a corridor might well take 30 or so. The same staircase will go through your entire fort. People say dwarves might fall down the stairs and die. This however only happens if someone is already fighting in your fort and then they are likely do die anyway. Besides no fighting in the fort is more or less something you always should strive for anyway.
Dont have a corridor/staircase of only one space wide thats going to be used by many at the same time. It increases FPS when the dwarves have to constantly creep under each other and wait. Plus it somewhat increases time to haul. The 3x3 staircases you have are just fine and the 3x corridors as well. The trade depot one should be expanded however.
You dont want to have idle dwarves. Granted this is difficult for beginners.
2-3 idle dwarves at any given time is fine since dwarves tend to be idle for few seconds between each task but thats it. How I handle it: Each dwarf has a specific task it should do. Always have your miners mine something out. Carpenter only does carpentry, mason only does masonry etc. Have these dwarves constantly working creating something (carpenter can of course stop if wood is scarce). Good things to have loads of are
bins, doors, tables, chairs (once your legendary dining room is complete place a table and chair in each of the dwarves rooms),
blocks (for dwarven projects like towers/walls, blocks save loads of time there due to stone being difficult to haul),
coffers (a coffer for each dwarf room and loads for each site),
spiked wooden balls (The value on these is insane. A good trade dwarf will easily take everything the merchants have for 20-30 of these made by a good carpenter),
beds (each dwarf should have their own room, if they dont they get stressed),
pots (more barrels are always nice). Its also good to have atleast one hauler for each dwarf on loop. In order to control that the dwarf makes the task you want you can have the haulers only do hauling and the crafters only do hauling. Mining can always be done constantly and will never cause trouble. If you feel like you have too many open mined out areas increasing fps then you can just wall them out and open them up later if needed. If you feel overwhelmed by the production just turn it off for some time.
Wood is a resource you want to have a plan for, since unless you know how to work with magma its going to get used both for fuel and various other things. Ex:
beds can only be constructed out of wood. Exception being is that you want to make wooden bins since
bins are incredibly useful and the quickest way to make them is through wood. Unless you are really lacking in wood bins are worth it.
You do not want to make wooden barrels. Barrels are made out of stones from your stonecrafters (called pots). Exception is for the rare building that needs a barrel it in order to get built. Even if you are never going to run out of wood due to being in a dense jungle there is still going to be a lot of hauling done if you plan to use massive amounts of wood.
Have everything your dwarves are working on
as close to the central staircase as possible. Granted this makes the fort much more boring so its not for everyone. However if all of your workshops/farms etc are close to the central stairs then it reduces the distance dwarves are forced to haul things by a lot.
Dwarves are dumb when it comes to where they dine. If you want a legendary dinging room that gives ecstatic happy thoughts then you need to place your food next to it. The dwarves are likely to eat at the closest spot compared to where the food is. It is smart to have a separate storage for seeds next to the farms.
Dont forget something the dwarves can drink out of. If the dwarves drink straight out of pots/barrels without jugs etc they get a bad thought. These can easily be made out of stone at stonecrafters.
You want your refuse pile to be just outside your fort entrance so that the dwarves dont have to go far. You do NOT want corpses to be stored there. Corpses should be stored at a decent distance from the fort entrance because dwarves get bad thoughts from seeing dead goblins/humans/elves/zombies. This bad thought will stack.
From the traders you specially want:
books (some dwarves really like to read and making books is complex, trading for them easy),
complete instruments (making instruments out of parts is somewhat annoying and you dont need many, trading for few of them completed is easy)
wood (its cheap and usually quicker to haul from depot compared to anywhere else),
other types of food than what you have (same food/drink as usual gives bad thoughts, cheese is good),
animals (to mix up food and butcher in order to get leather/bone for strange moods+ some animals like tame cave crocodiles and tame grizzly bears are damn useful in a pinch),
bars (usually cheap, good for training and whatever you can make out of them will be worth more),
cloth, thread, leather (needed for bags, clothes plus its saves time to trade for this),
gypsum plaster (for hospitals, very useful if you have injured dwarves),
Milk (cheap and easy to make cheese out of). Do NOT trade for trap parts, sheets, barrels, bins, coffins and other similar furniture unless you really need them. They are usually overpriced and you can easily make them yourself.
Good items to create in value for trading is trap weapons (in wood or silver spiked balls are good choices), clothes (masterwork dyed clothes are worth a suprising amount), gems (easy to haul, easy to trade), armor/weapons of a inferior material (you can train your weaponsmith/armorsmith in copper items and then trade them all away).
Elves are annoying to trade with. Good things to trade with them are all your gems (save them for elves really) and clothes. Dont trade for wood weapons/armor, they really really suck. Be very careful not to include any wooden bins or similar when you trade, this will upset them.
You want to look out for dwarves that value knowledge and think it has value. These are good for being scholars. There usually are pretty few of them around. If they do not value knowledge then they are very poor scholars. If it says nothing about knowledge its fine. If they value knowledge then they are much more likely to spend their time in the libraries doing scholarly stuff. The quickest way of checking this is hovering over their names in dwarf therapist where it will be listed among the things they value/dont value.
Use wheelbarrows. Piles of non economical stone next to the stonecrafter/mason is very useful, however these will only be quicker if they have wheelbarrows. The wheelbarrows will reduce hauling time by a third. You can allow the piles to use wheelbarrows by just changing their settings. The same goes for piles with heavy furniture, ore piles next to smelters, piles with metal trap parts etc. 20 or so wheelbarrows is likely to be the most your fort really needs, but it depends on how you do your piles.
A solid fifth of your fort can be dedicated solely to farming diffrent farms, brewing, hauling only food, plant processing etc. You want to have many diffrent types of food since the same food will give your dwarves a bad thought and they pick what they eat drink at random. This means loads of plump helmets are good in the beginning but later it should just be a part of all food you have. You want to have a big pig tail farm since its by far the easiest way to get cloth. You dont want the food to rot so dedicated food haulers is a must. A skilled grower actually increases the yield by quite a lot from each plant so the farmers should do farming and not much else. The loss of a single farmer is not the end of your fort so they can easily be hauling refuse as well.