University teams can include anyone involved in the university community- students, staff, faculty, alumni, mascots. However, this applies to a group or team, not an advocacy challenge. An advocacy challenge pulls riders in by county. An out of state student's location should not affect their ability to show up and contribute miles to the University's team. It only would affect their ability to participate in a local advocacy challenge.
A Strava club, or what we refer to as "Groups" or "Teams," is a collection of individuals with a shared community that specifically joined the Strava club.
Use both your personal referral link in your "Settings" on the Challenge website and the "Invite" tab on your Strava club page to recruit your friends and coworkers at your University!