I would like to know if having a negative contribution does not allow me to create groups, since I want to create a private group for the people in my school who are interested in learning to program and I can send them the problems from here and it is easier for me to have to correct what they send.
No, it doesn't. It's good that you want to help your friends learn programming, if you want any help just DM me on Codeforces. Good luck.