I'll try.
First, while the game is made by Larian, and they have added a little of their flavour to it, it's still NOT a DOS game, it's a D&D5E game.
In D&D, first level characters are weak as hell. You have very few options and very little differentiates you from other characters. Everyone has 1 action, 1 bonus action, and their movement in their "6 second" turn. Again, at first level there is very little you can do with that. As you progress, you start being able to do more with that. It's still 1 action, 1 bonus action, and your movement, but higher level characters can do much more in that framework. For instance, fighters will be able to multiattack for their 1 action, and thieves get their "cunning" action which gives them more options with their bonus action.
Truth be told, you actually have a bit more power at first level in this than you do in the P&P right now.