In Baldur's Gate 3 there are "something like 600 spells and actions," according to Larian's release showcase. That sounds intimidating, especially if you're not already au fait with Dungeons & Dragons, which is an arcane game that evolved out of tabletop wargaming in a dark and ancient lost age called the 1970s.
Fortunately Baldur's Gate 3 uses the 5th edition, D&D5E as it's known, which is the easiest version of D&D to learn and also the best. There's a universal mechanic that resolves basically everything you can do and a straightforward rule for raising or lowering your chances of success.