Additional team and channel-related features and issues within Microsoft Teams for Education
Hello Lindsey,
Since you already have team code, to join the team, you can follow the steps below:
1. Click Teams icon at the left navigation pane.
2. If you view your teams via Grid layout, please click the Join or create a teamat the upper-right of your Teams screen. If you view them via List layout, the Join or create a team option is at the bottom of your teams list.
3. Go to Join a team with a code (the second tile), paste the code in the Enter code box, and click Join.
If you need further assistance, please feel free to let me know.
Regards,
Seven