First, if you don't have it already, you need to download and install the Microsoft Teams Client. You can find that here: https://teams.microsoft.com/downloads. (If you do not have administrative rights on your computer, contact your local desktop support to have them install the Teams client on your machine.)
After you get Teams installed, you sign in with your full WSU Email Address and Password.
You should see the Teams you are a Member of when "Teams" is selected on the Left toolbar: