How can I create user profiles in drupal 7?
In Drupal 7, users accounts are fieldable entities like nodes. From Administration » Configuration » People » Account settings, you can add fields and configure their display on the user page (ie. /user/$uid). 

For a more complex setting with multiple profile types and separation of accounts (ie. user) and profiles, you can use the Profile2 module.

You can then use Views to easily crate blocks and pages to list users and information from their profiles.