There are plenty of ways to go about creating a profile type page, first you have to ask yourself, what do you want the users to be able to do. If you want to create a social media type system or a forum based application.
Second, once you decide on the type of system you're building, start looking for similar software that can already do what you want. If you want more of a challenge and create your own from scratch, start looking at the source code of other systems that does this. Look at the way they handle data through the database, look at how the database is designed etc.
Third, Choose the technologies you're going to use. Start with the basics, like PHP and MySql for the database. Look into different frameworks for PHP like ZEND or Lithium. Start designing the database by drawing out an ERD diagram or if you have a really simple database structure, look into more lightweight Database like mongoDB or NoSql.
Forth, once you're ready for more PHP complexity, start designing the architecture of your system, one of the more popular architecture out there is the Model View Controller architecture. I strongly suggest reading the tutorials posted on http://www.phpro.org/, It's really advance stuff but it's well worth the learn.
Fifth, once you're done with the database design, software architecture etc. Start designing the user interface(UI) and designing the actual look of the system. Start doing some research on security and best practices on how to prevent them.
Well if you got that far, you should be all set. The development process always scares the hell out of me but if you get to work in a team with other developers don't pass the opportunity.