A Weeb Plays Balder's Gate 3 for the Second Time 

Yes, Minthara is a tough fight. Keep in mind certain things cost an action, a bonusaction or a reaction. Jump or shove, attack or spell mostly cost an action. Certain attacks, drinking a potion or spells cost a bonus action. A reaction happens on the enemy's turn. When you want to attack either move up next to the enemies character or click on the enemy. Your movement is determined by your blue meter on the right side of the screen, once it is empty you cannot move any more for that turn. If you flank enemies it will threaten them, giving you better odds to hit. Dazing them or knocking them prone forces the enemy to use his action to stand. For example Laezel: move her up to the enemy, use bonusaction: pommelstrike to potentially daze and attack with action. You keep action surge for the next turn to attack twice. Gale is squishy so get him up high to cast his spells from or out of enemy's range or have him hide out of sight. I basically have gale do magic missiles or grease to hit the enemy or set up a difficult terrain, forcing them to either go around or potentially fall prone and once the targets are greased up all one needs is a fireball. If you've equipped expedious retreat it will allow Gale to dash as bonusaction. So you need a turn to cast it to set it up, but once there you can do your action and then move extra as bonus action to get our frail wizard out of range. Hiding and sneaking is generally a good idea, toggle group sneak and stay out of the red. For then you are visible. Turn off the torches to help you hide in darkness. You can check out weaknesses by examining the enemy. Rightclick on the enemy you see potential weaknesses. Ah the hits and misses, so there are dice rolls behind the screens, determining whether you hit or not, it will be challenging the enemy save roll. So sometimes you miss. This is how DND works. You roll to hit and upon a hit you get yo roll the damage die. This is why you wanna use the terrain against them. Throw a bottle of grease or light up a barrel of oil. Also your character will walk in as much a straight line. You see the path your companion will travel, if you send it through acid and fire (it will light up red) you will take damage. Armour Class or AC determined your defense and also the higher the AC the higher the enemy has to roll to hit you. Barbarian has unarmoured defense giving it resistance to certain damage types. Spellcasters can use Mage Armour to up their AC, but I prefer the Shield spell paired with the Lucky feat. You basically use a reaction when the enemy attacks you. It costs you a spellslot each time, but your character basically goes NOPE Motherf-er, your hit is a miss. 'Magic Missile' however never misses. It will go around corners for you. Sure it isn't a big damage dealer but it is consistent. Also the damage is also determined by hidden dice roll: A fireball for example has a damage die of D10 which can result in 1 damage or just as easily its max total 10. As it is a die with 10 sides. This is why you want to stack damage or lengthen its duration. If the target is too close shove or (warlock spell) eldritch blast it, gust for wizard/druid/sorcerer. Don't provoke opportunity attacks, get up above the enemy, preferably so you have the high ground. Low ground will cause greater misses. If you want to ressurect your partymembers you have ressurrection scrolls all party members have one. Hopefully I've managed to explain things a bit better. Also murder that Arcane eye (floating orb) it tells them of your presence. Snipe it with a hidden magic missile or sneak attack from Astarion.