To reorder your teams, select Teams 
and then choose and drag the team name anywhere in your teams list.
Note: Every team you're a member of is shown in your teams list, either under Your teams or inside Hidden teams located at the bottom of the list.
Hide teams that you don't often use
To help keep you organized, we'll automatically move teams you haven't visited in several weeks to the Hidden menu located at the bottom of your teams list. Those teams will still update with any new activity and you can visit them at any time.
You'll be informed whenever a team gets bumped down to the Hidden teams menu and given the option to either accept the move or undo it.
Move a hidden team to your list of visible teams at any time by hovering over that team and selecting More options … >
Show.
Your teams list is the same in your mobile app as it is in your desktop app. To reorder your teams list in your mobile app, you'll need to go to the desktop or web app and make the changes.
