Universal Studios Hollywood

Balboa RV is a residential pit in a low income area backing up to Van Nuys airport (the now defunct side which was the National Guard station). There are really no nice parks in the Los Angeles area, LA is just not RV friendly. Walnut Grove RV is also a residential park backing up to the Metro Link line, a block from the Northridge Mall with section 8 housing across the tracks. On this side of town you really need to go farther out. Travel Village RV park in Valencia backing up to Magic Mountain is very nice. Also Castaic RV Park a bit further out near Magic Mountain is nice. Both are about a 45 minute drive to Universal without rush hour traffic. With traffic, your best bet could be 1 to 2 hours, it is only about 30 miles. If you want to go further out, Ventura RV park is an option, quite a bit further, but you can take 126 around and then pass Magic Mountain on the 5 and head to Universal. (I'm referring to Six Flags Magic Mountain). If you are only planning a day at Universal, staying in Anaheim is still an option, about a 1 hour to 1.5 hour drive to Universal, just plan your day around traffic, heading to Universal after 10am and heading home to camp when the park closes, like 11 pm. Again it is not the distance it is the traffic.
Happy Trails.