User Plugin

Hi Team,

I am in need for a plugin. Please help me out.

I am trying to build a website for my school. I want my school students to register themselves on my website and login so that they can write examinations online.

I am unable to find that kind of plugin. I have found out some plugins like zm Ajax(which I am unable to make it work) and one more is profile builder (this is not for the users on my website. this is for the users on wordpress where they can navigate through dashboard)

please help me get a registration and user login plugin where I DO NOT WANT MY STUDENTS TO VISIT MY DASHBOARD. THEY HAVE TO REGISTER, LOGIN AND WRITE EXAM AND LOGOUT AND LEAVE.

Please help me out.

Many thanks in advance.

Regards
Sri