Leroy,
Launching with your boat out of Cabrillo is no problem. There is plenty of open parking to rig your boat, and a nice ramp. There is a very long dock on one side,(portside of your boat), so you can float the boat on and off the trailer, (see the first photo). You'll need to extend your trailer tongue to launch. Parking I believe was $15. a day for your vehicle and trailer. We launched out of there last summer on the "Catalina's to Catalina" cruise Debbie and I hosted. We overnighted at California Yacht Marina, just a short walk from the boat ramp. Very nice slips, nice clean bathrooms and showers. But, they only sell gas and ice at the marina. There are no restaurants close by, or grocery stores. You have to keep your trailer attached to your vehicle, so once you launch, you're pretty much committed there. We sailed out of Cabrillo and went to Avalon first. Stayed several days then spent a couple days at Two Harbors before returning to Cabrillo. It's my new favorite launch site in L.A. Attached are some photos from the trip.
Don