Most people going to Levi's Stadium from the train just walk. It's about a mile.
On Super Bowl weekend, only Super Bowl expresses (limited stops, and Super Bowl ticket required to get on) will be operating on VTA's light rail line in that area; regular passengers have to get off and take a bus bridge going around the stadium area. Stations near the stadium will be for Super Bowl attendees only. See VTA's Super Bowl service notices:
[
www.vta.org] - regular riders
[
www.vta.org] - Super Bowl attendees
[
www.vta.org] - Parking lot closures for Great America (the closest) Amtrak station
Caltrain service to the stadium requires that you get off at Mountain View and take a light rail shuttle to the nearest station (about a mile walk).