Recently, I started my second campaign in Baldurs Gate in addition to the campaign I play with my wife in co-op. My wife and I opted for the easiest difficulty in our playthrough since neither if us ever played similar game.
This time I felt like it would be such a breeze since I already know a bit more about the game and DnD in general. I opted for the balanced mode with my new character and started going through Act I and boy oh boy do I get wrecked almost everywhere. Multiple of my characters already died and I had to revive them.
Characters
Including Gale, which in turn triggered cool mini-quest to revive him, but the magic aura around his dead body killed Astarion multiple times.
I feel very scared going into each combat and trying to plan as much in advance as possible (keep in mind I mostly know what awaits me there, because I've gone through Act I already).
Where I got wrecked
I got wrecked at the church before you get to Whithers, I got wrecked by the hyenas and gnolls by the caravan road, I got absolutly wrecked by the Paladins of Tar and
I just don't know what am I doing wrong.
My party
I play as high elf paladin and most of my encounters so far I've had Astarion, Gale, and Shadow in my party. I feel like the only actually useful member is Astarion. I probably don't know how to utilize Gale well enough and my Tav paladin just feels like a paper-thin wall between the enemy and the rest of the party.
Are these early encounters in Act I intentionally challenging so that the game "force-teaches" you to utilize everything at your disposal and will it get easier later on or am I just on the wrong path with my character and my party? Honestly, I can't imagine going through the goblin camp in this state.
Those three fights are the "big ones" in act 1, probably as hard as the goblin camp, what level were you when you did them?
The easiest difficulty make combat a faceroll (which is a great way to experience the story, if that's your primary goal); balanced makes you care about what level you are for the encounter, positioning, and your party make-up; Honour makes you think about terrain, party make-up, item use, damage types, and resource management.
Your ranged characters shouldn't be close enough together that they can be hit with an AoE, and ideally, they are somewhere that gives advantage.
Party make up
Shadowheart is mean and stupid, and she's also easily replaced as long as anyone else in the part has "Guidance".
I think I was level 3 for the church and level 4 for the other two fights.
party
I mainly carry Shadow because of the Guidance and I want to try romancing her (so I can build up the approvals) but otherwise my paladin Tav can heal as well. I might try switching her for Lae'zel or Karlach.
Just south of the druid grove there's a hill you can climb up that has an amulet that gives Guidance. If that's your only reason for including Shadowheart, that might be a good alternative.
If you are going to keep Shadowheart, I'd recommend respeccing her to switch subclasses (I'm a fan of Tempest cleric, but there are several good options) and fixing her stats (like choosing either STR or DEX rather than splitting both).
Make her a vengeance paladin. She’ll hit like a truck and can still heal. Also thematically she’ll still have the sharran choices as she is identified as a paladin of shar (the only one in the game).
Make your paladin a 2h smiteadin with a bard dip for college of swords maneuvers. Yes bring karlach and laezel and all 3 of you single-target 2h shredder your way through the enemies.
Assassin astarion is a monster and can usually sneak attack kill targets in one shot. Especially if you go the ranged route and add the extra base damage from that one ranged feat.
Once gale has fireball you can trade him out for astarion and just huck those things around as much and as often as you can and rest every time he's out. He's also really good at magic missile spam with those electricity items.
Most importantly, you should always prioritize killing one enemy at a time so that you're quicker to remove them from the turn order and prevent them from doing damage on their turn. Basically never split damage with your single target party members.
To be fair those are definitely the toughest fight in Act I. I've only played on balanced, so I can't vouch for story mode. I would highly recommend adding Lae'zel or Karlach to your party though. This is a good idea.
I'm on my first honour play though, just hit level 11, and my party is the same as yours, but swapping the person who is stupid and mean for the second person you mentioned.
It might be a matter of changing battlefield positioning, or focusing on "action economy" if you're not already. Unless you are doing an AoE, someone with concentration needs to be interrupted, or there is an odd mechanic, it's best to kill enemies one by one. That means one less person is attacking you each round, and this advantage grows each person you kill off.