In order to complete your profile, you will have to click on your username tab on the upper left side. When you click on this option, you will get a dialog where you will be able to see your profile details. On its upper right corner, you will see an "edit" button.
If you click on this button, you will be redirected to a page where you will have to log in. Once you've entered your email and password, you will be taken to your profile and you will be allowed to edit and complete it.
You can add a profile picture, change your username and write about you. Feel free to complete and give as much information as you feel comfortable with.
Bear in mind that while in the campus, all this information will be available for people that is in the same space as you are. By the same token, you will only be able to access the profiles of those users that are in the same room as you are.
Note: your username cannot have any spaces.