It was easy to access the train; Route 61 to the north takes you to the train station in Perris, which seems like the only train station on the Riverside line. I reviewed the route, and some nice places to visit are the following:
Perris Valley Line Route
University of California Riverside in Riverside City
Mission Inn Museum in Riverside
Knotts Berry Farm in Buena Park
Disney California Adventure Park in Anaheim
The Broad Art Museum and Museum of Contemporary Art in Downtown L.A
Calle Oliviera in Downtown LA
Old Town San Diego in San Diego
The Beach in Ventura
All included rail systems (Along with the Arrow Service and Pacific Coastliner) take you to San Diego in the South, Redlands in the East, Ventura in the West, and Lancaster in the North.
Going on the train is not only easily accessible but very relaxing. L.A. is worth going to alone for the free art museums. I was amazed at what they showed off in the Broad and Museum of Contemporary Art.