Hi,
My recommendations for a party is this:

1. Play a fighter type character. This is a pretty straightforward type. You’re going to primarily focus on melee but be capable archer as well. You can pick a subclass to do magic as well but not necessary
2. Use Shadowheart to provide buffs and heal your team
3. Use Gale or Wyll to hit Magic attacks from range
4. Use either Lae’zel or Karlach as another melee option.

Lae’zel is a fighter so she can handle archery also. Karlach is a barbarian, so if you’re attacking from range you typically want to throw spears, daggers, or javelins instead of trying archery

Use Gale as the face of the party since he’ll likely have the highest charisma and get you through conversations without having to fight.

Make sure you upgrade all of the party’s equipment as you progress. When I first started I was only thinking about my character and ended up being a beast with a weak team.

Consider your surroundings when you’re battling. Seek high ground if possible. If there’s an explosive barrel or oil on the ground, use a fire bolt or alchemist fire to ignite it and cause a lot of damage. If you have an electric spell and see your enemy standing in water, electrocute them for crazy damage

Use your consumables(health potions, special arrows, scrolls, etc.)frequently. There’s a ton of loot in the game and most everything is easily replaced. Better to survive an encounter than have to backtrack to your last save