MacBook Pro is managed by Organization

Hello, my brother bought MacBook Pro 2017 on "amazon renewed" 6 months ago. Now he sent it to me and I wanted MacBook to be like new, so I erased the disk and reinstalled macOS. After this, I found out that this Mac is "managed" by an organization. Also, I found the "Profiles" section in System Preferences and there I found 19 different profiles. I'm trying to delete them but they are unremovable as I found out. It's managed by the University in the U.S. Also, there is an "Other" sign-in option when I open a MacBook. and I can't remove it from "Users" because there is no such account.

1. Can you please tell me how can I remove these profiles? We paid for this and I want to use it.

2. If there is no chance to remove them, will it be blocked by the organization or will it harm my files? Is there any chance that they will block the laptop or can they? Will it interfere with my work? Do I have to worry about this?

3. What do you think, we bought a stolen MacBook or from a student?