Just playing Baldur's Gate 2 EE for the first time (haven't played 1) and am getting my ass kicked already in the first part. Any tips for a beginner?

I just lost two party members to the dwarfs and don't know how to bring them back. Also, I frequently get screwed over because I realize that not all my characters are actually attacking enemies. Also whenever I select everyone at once my squishy player character, a gnome illusionist, insists on being at the front. I'm pretty sure I need to load back and start over. Any tips for doing this right?