I would strongly suggest you to take up the rapid application development course, because this is basic and handled in Mendix academy a lot.
- Mendix has default login mechanism out of box
- With Mendix you can set security roles and permissions, have role based home pages etc.
But these are like basic building blocks of any application. So, once again, sure Mendix rapid application course would help you with a great start.
Besides that its still wednesday and monday is 5 days ahead. The rapid developer course is still doable as it is formally 3 days. But for young students like you doable in half of the time ;-)
Another option is to take the short cut and go through this learning path: https://academy.mendix.com/link/paths/40/Mendix-Basics
Nice, But that is too late. I need a tutorial or something until sunday. I have a deadline on monday for university.