You must fill out basic profile information in order to cast votes, leave comments, or follow other users.
1. Go to Account settings page.
2. Under Profile tab go to "Information" heading, and fill in your first and last name.
3. Under "About You" heading upload a profile picture.
4. Then under "Social Media" add your contact links. There has to be at least one verifying your identity.
5. At the bottom of same page press "Save changes".
Need more help? Email firstname.lastname@example.org or tweet @500px_help