Los Angeles is served by Amtrak at Union Station at 800 N. Alameda Street.
Needles, CA. From there, you can take the Southwest Chief east to Albuquerque and Chicago or west to Los Angeles.
You will need to first get to downtown Los Angeles to get to the Union Station train terminal. From there it may be possible but check with the train people such as Amtrak to be sure.
Union Station is not the name of a train but the name of a train station so no one rides it. There is a Union Station located in Los Angeles, Chicago, Washington DC, and a variety of other cities.
Douglas - Los Angeles Metro station - was created in 1995.
Firestone - Los Angeles Metro station - was created in 1990.
Fillmore - Los Angeles Metro station - was created in 2003.
Soto - Los Angeles Metro station - was created in 2009.
Vernon - Los Angeles Metro station - was created in 1990.
Slauson - Los Angeles Metro station - was created in 1990.
Allen - Los Angeles Metro station - was created in 2003.
Pico - Los Angeles Metro station - was created in 1990.
Indiana - Los Angeles Metro station - was created in 2009.