DataAssist could be the extension that you want to use, but i recommend looking into using Security Assist, because you are creating a registration form. And once the user is registered you would use Universal Email to send a confirmation email.
This link contain a few documentation that could help you get started:
securityassist/
Once you have your registration working, you could then start on the profile page where you could customize the page to show information for each user.
But before you start on any thing, make sure you have your database set up already and ready to go.
Let me know if you still have any questions.
