You can personalize your username, avatar, location and more by heading to your My Collection tab in the top bar of any page. From there, click on the three dots on the right-hand side of your profile and click on the Edit Profile button.
To change your username, you can either do so in the Edit Profile menu button on the line that shows your username or directly on your profile page as shown below.
Below the username section in the Edit Profile menu, you can select your location here which will appear on your public profile and will also be visible when collectors are filtered by specific areas. In this menu, you can also update your favorite team and collector title and link your Twitter or Discord social media accounts to your profile.