Baldur’s gate 3 is heavily based off DnD 5e, so many(but not all!) tips applicable there are also applicable here.

In short, it’s an action economy game, so the best thing to do 95% of the time is either killing an enemy as fast as possible, or stunning an enemy so it can’t attack you while you murder the rest of its group. Things like healing, buffing are usually best done out of combat, though bonus action heals like Healing Word are often useful and you shouldn’t discount buffs, just try to apply them pre combat.

Crowd Control spells like Grease and Web are vital for lvls 1-5. This thread covers some fun combos that people have been using.

The Sanctuary spell is insanely useful for restricting enemy targeting.

Positioning matters. Not just Fontline vs Squishies, but try not to place your party members near chasms and setup choke points to hold.

Generally speaking you will want a Frontliner, Skill Monkey, Arcane Caster, and Divine Caster in a party.

Some feats like Great Weapon Master, Sharpshooter, and Tavern Brawler punch way above their weight class. Those three are generally the only ones that beat taking an ASI at lvl 4.

This is the build I used for Lae'zel and it crushed Tactician.

!baldurs_gate_3@lemmy.world

There's a way to easily respec both yourself and your party so there is no need to worry you'll level up wrong and need to start the game over. You can do it as many times as you want until you get something you like.

Spells are a very limited resource and should be saved until they are absolutely necessary.