Glad you asked, @Mile! You certainly can change your Community username. When signed in on the Ring Community, your username/ avatar will be visible towards the top right hand corner. Clicking on this area will present you with several options, in which "My Settings" is the proper choice. Once you are on your profile settings page there will be a "Username" option found under the "Personal" section.
Feel free to also check out our New Community Member Checklist for tips on creating a username, changing avatars, and more. I hope this helps!