Greetings from the IE! I saw from another post that you're new to camping altogether. I'll mention two campgrounds in San Diego that you might like while you get used to your trailer. (In other words: a lesser degree of stress for your initial voyages, level spaces, hook-ups, and other inexperienced campers around you. You'll blend in. I know from my limited experience.) Both are family-oriented parks that should keep grandkids busy. They are close to stores for anything you realize you forgot. Both do get crowded.
Look at Campland on the Bay. It is on Mission Bay, and freeway close off the 5. It has a small beach and marina. I don't think they have pull-thru spaces, unless you really want to shell out $$ for a deluxe space.
The other campground is the San Diego KOA. It's actually inland in Chula Vista, off the 15. KOA has pull-thru sites, which is a blessing to new trailer owners who don't want to (try to) back in and embarrass themselves.
Both have websites that you can look at a map to get an idea of their layout.