As a team owner you have the ability to manage the team settings.
To change your team settings go to the team name and select More options > Manage team. From there, you can access your team Settings tab, which lets you:
Change or Add a team picture.
Set member permissions (like allowing them to create, update, or delete channels and tabs).
Enable @team or @[team name] mentions in a channel.
Enable team members to send GIFs, emoji, and stickers.