As the creator, you can only edit teams that you created in the Experience Manager. If you pre-created the team, you can hover over the team on the Participants tab and select edit on the right-hand side to change the team name, access code or profile picture.
If a participant created the team, as the creator you will not be able to edit the team name or profile pictures.
As a participant, if you created your own team, you will be able to edit your team name by navigating to the You tab in the bottom-right corner of the app. From there, select the gear icon in the top-right corner.
You should see a small pencil in the upper right-hand corner, clicking this will allow you to edit your team name. If you do not see a pencil, that means that your Experience creator pre-made the team, and you do not have access to edit the name or photo of your team.