User auth custom page

Hello,
I recently created a simple cookie based user and password login script using PHP and MYSQL and it works beautifully but now I have hit a roadblock. This is for a school and the reason why we have it is for students to view their own grades and no one elses… any ideas on how I could add to my preexisting login script to make them goto a custom page with maybe their grades etc… pulled from the db and into a template?
I can show code examples if anyone is interested.

thanks