Multisite custom dashboard and user store/page

I have created a multisite store using marketpress and buddy press. I want my users to signup to create store and only have the ability to add in things like custom header, store name, store descript, owner name, and a few other custom fields. I am a bit lost on how to do this...do I create a page and then a database and put these users into a database and then query it with php to show on the page, or is there a more automated way to accomplish this.
Thanks,
Kate