New to Jiu Jitsu, Questions

Hello, I’m brand new to Jiu Jitsu, I have attended 3 classes, but I feel like I’m not picking up the lessons, I can’t even figure out the shrimp move, I know I’m really early into this but I feel like I should be able to retain more information, I’ve kinda just been struggling my way through these classes I love doing it and I’m having fun but I’m worried that I’m just in able to be coordinated and able to pick up the lessons, I have never done sports or anything like that in school or outside of school, I’m 21 btw, I’m able to retain little bits of information but I just get confused when practicing the different moves my professor shows me I don’t know where to grab or I can start a certain take down but forget what I’m supposed to do mid way through it. Is this normal? I will keep going to classes but I feel like the other white belts are able to pick up and accomplish the moves way faster than me. Any advice? Thank you!