excuse me, well i'm just starting learning php, and i got a homework to make a login form to access some information. i already done that, but my lecture add a some problem.

the problem is:
- what if the web have an admin and many user. what code is used to determined admin or user at login?
- how to make a form to edit the contain of table or database (for admin page)?

sorry, English is not my mother language. I'm from Indonesia.
could anyone help me, please?