Depending on what race you started with, monsters may have more speed then you, which means they will occasionally take multiple turns depending on the difference.
Early game, delivery and escort quests are your main source of income. I wouldn't bother with combat missions as you're probably not properly set for them regardless of what class you chose (unless you're playing as a god race or something). Be wary of time limits, and things missions with ambushes like "Beauty and the Beast" quests. Seven league boots trivialize most of these missions, so keep an eye out for a wish.
Drinking from a well can be bad, but can be mitigated with some knowledge. Stat downs are as common as stat ups, and most mutations are often stronger versions of both. Unwanted pregnancy can be aborted by an easily obtained potion of dye.
Thirst... is a new mechanic which a lot of players find annoying, but it's not too hard to deal with. Use your house board to put down a walkable water tile and stand on it. Your hydration will gradually increase; same for water tiles you find in dungeons.
For more portable hydration, you should look into obtaining a juice mixer or pot of fusion. Juice mixers can usually be found in the cyberdome for about 6k before negotation, while pots of fusion is occasionally found in general/furniture stores. Juice fruits from fruit trees that you find in towns, and crimberries can be turned into 8 blessed crim ale in a pot of fusion with 2 alchemy skill, which also fetch a pretty good price in shops.
Highwaymen will attack randomly if you have any form of cargo, and giving into them will result in them taking your money, so I wouldn't recommend relying on them until you're fairly strong. So consider scavenging instead. By pressing enter on a tile without a building or city, you can freely enter the wilderness. Hunt down edible wild plants, healthy leaves, crimberries, chestnuts, and api nuts. Of those listed, only edible wild plants rot, and learning cooking will up their nutritional value. The wilderness regens each time you enter it, so you can build a sizable stock of portable rations.