To mint coins, you go into the Economy screen (looks like a pile of coins) and drag up the Treasury slider. This will increase your inflation, which is bad if it gets very high. It raises slowly though, so its ok to mint once in a while.
You gain tech automatically from all the money your treasury doesn't consume. Your nation makes quite a bit more money then you can actually spend, but this money goes towards tech development. Minting takes money away from tech development and into your hands to spend on different things. So full minting -> no non-treasury ducats -> no tech investments, if that makes sense. However, you can direct what money goes where in the economy menu by moving around the sliders!
Units come from land tech. You'll get a notice when more units are available.
You couldn't assault because Portugal were the first ones there. The first nation in a province gets to decide whether or not they will assault. In this case, Portugal decided not to assault the fort.
Alright thanks
Can you explain the sliders and their benefits/consequences to me please?
And, those bastards! I wanted to just get rid of Granada right then and there. Which leads me to ask, what about claiming provinces? How does that work?
Do you mean the Tech sliders, or do you mean the Government sliders (the ones in the page with the book and gavel.)?
If you meant tech:
Government isn't too important if you're playing a European nation. You should have a fairly decent government type to start off with. However, at key levels you gain National Ideas. I think the first is level 6, and the next is level 12. National Ideas are little bonuses you can pick for your nation when they become available that will give you certain things. For example, if you pick the Military Drill national idea, your armies will have +1.00 Morale!
Production and Trade mostly open up buildings as you go through them while giving you tiny bonuses along the way. You don't have to pay too much attention to these sliders.
Naval and Land open up units for the navy and army. Land is usually the most important. It also gives you tiny bonuses along the way.
Stability is very important. It ranges between -3 and +3. Having +3 stability should be your #1 priority. The amount of time it takes to get more stable depends on your size; for example, a tiny 1-province nation will go up a stability point every month! Low stability = more revolts, less tax money, and overall badness.
About claiming provinces, that depends. For example, in your war with Granada, because Portugal got there first, they would occupy that province. Once you occupy a province, your war score (Higher war score = better peace deals. Goes up to 100%) goes up and they no longer can control that province until you sign for peace or they take it back. Once you have enough war score, you can go into the Sue for Peace screen and select which provinces to take; if you selected the provinces that Portugal occupied, they would take those provinces for themselves. You would take the provinces you occupied!
Oh, and you can't take the capital without annexing the country. Annexing is when you and only you occupy 100% of their territory. Annexing will erase them from the map and give you all of their land. This can range from a very good choice to a very bad one. Your infamy will skyrocket, making everyone hate you, unless you declared war with a casus belli (cause of war) that let you annex for less infamy, revolts will take place, etc... but all that land is yours, now!