Have fun is the most important thing.
You can't do anything wrong, even if it looks that way ( there are always second, third... playthroughs to experience things differently).
I would recommend talking to everyone and go everywhere, the game lets you. If a character is recruitable, take them in, they might surprise you.
Avoid spoilers, it's more fun that way. Don't go into the story sub forum here or the suggestion one, both can be very spoilers.
There are a lot of consumables, spellscrolls etc. - use them and don't hoard them. Most of them are not unique.
There are a lot of ways to beat the game - go with the flow and what seems right to you. Chances are, the game will let you.
And again: have fun.
