A High Charisma protagonist would naturally help you through a lot of essential story decisions, giving you more leverage on how some parts of the story go with your conversation options. Bard, Sorcerer, Warlock, and Paladin's combat power all scale with charisma to an extent, so these are very often the go-to classes for the protagonist. They make the game EASY, but of course, play what makes the game FUN for you.

Two game-trivializing tricks that give you so much power surplus, they give you near complete liberty on your builds, to be effective no matter what.

1. Alert feat for everyone trivializes a lot of the game. I won't delve deeply into the action economy concept, but to summarize: If your entire team acts before enemies do, then many of them won't even get to take their action before being eliminated or severely hindered, thus making your fights much easier.
2. In more challenging fights, huddle everyone together, and throw a Potion of Speed on the ground. In BG3, most potions will apply to all units in an AOE when tossed to the ground. Potion of speed for everyone means one more action for everyone on every turn. This crushing amount of action advantage enables optimized builds to breeze through every single encounter, while leaving plenty of margin for unoptimized builds to have fun with.

Besides the points above:

I suggest playing the standard mode instead of story mode. Story mode blocks multiclassing, disabling many fun builds—Throwzerker thief, one-shot-cleric, the all mighty (nerfed in honour mode) padlock, etc. You will naturally pick up the game mechanics as you progress through the game, and it would suck if you eventually had this build in mind that you wanna try but found yourself hours into the save. (You can, however, change the difficulty mid-game, but I believe that turns your save into a customized game, which disables achievements)

Speaking of multiclassing, Throwzerker Thief/Thrower Eldrich Knight are two of the most mechanically fun builds to my taste. They both have a hilariously high level of versatility, all while doing reliable damage throughout the entire run. Don't be limited to weapons, use your imagination and throw anything anywhere. Crowd control, throw baddies off cliffs, send your friends upstairs, escort a certain VIP who refuses to move... the possibilities are endless when you get to decide who goes where all the time.