I’m 100% sure I’m gonna fail my test that

So for some background at this place I work my assistant manager got me into the school of that trade to get a higher credential and the company paid for it, it seemed cool at first but after being there for a few months and trying to study I’m 100% sure I’m gonna fail every time I study I get everything wrong I don’t understand anything in class and I feel like this was a huge mistake even agreeing to do this when i fail these test I don’t even now what I’m gonna tell my assistant manager hopefully she’s not mad and I’m gonna be a failure at that job for the rest of my life at that job. All my friends are now gonna make fun of me because I failed. What should I do Reddit