Lake Perris... You will pay a fee, State Park and boat use... It's very popular with windsurfers (well, it was when I was going there) I only used the ramp once, after that I launched my Nacra off the beach in Sail Cove. There's no ramp, just launch off the beach, which will be a ways since the lake level has been kept at a low level for years (problems with dam), If it's not crowded you can just leave everything down near the water. anyway, it's shallow and there can be some rocks..just be careful.. walk the boat out into deeper water before getting under way. Coming back you'll need to pay attention. Otherwise, the sailing in that area near the dam can be pretty nice.... but... it's limited and you'll get bore with it after a while. So If you have the whole day....
Go to Mission Bay. Launch out of Santa Clara Pt. No launch fees there. Next to the ramp, which is on the south side as you enter the area, is a small beach you can finish rigging and get the rest of your gear loaded. There is a dock at the nearby Mission Bay Aquatic Center that you will need permission to use temporarily if you don't want to use the beach. There are parking spots for cars with trailers adjacent. I sailed there for many years on my Laser and Nacra.
Do all your sailing in Sail Bay, there is a beach surrounding it that you can access, either anchor or run up on the beach.... be careful about leeward shore conditions on east side of Sail Bay.
If you want to explore the back bay, there's a privately owned ramp and facility at Camperland on the Northeast corner of the park. They are pretty cool about letting the public use it though, it's a pretty popular spot, lots of social activity going on besides the boating. I left by Nacra there overnight, and they didn't charge me,,,, There's also a large public ramp in at De Anza cove, exit on claremont, you can see it from the freeway. You might try to sail around Fiesta Island...that's where the famous "over the line" softball even is held every summer.. but the wind is fluky. That said, I can't think of any reason you'd want to take your boat there when it's so far from the good sailing over by Mission Beach and the jetty/ocean. Plus there's speed boats buzzing around... yech. So.... Mission Bay Park is a large area, but with a 22 footer, I suggest staying on the western side near Mission Beach, because as you gain confidence with the boat you will want to go out into the ocean....and once you do that... well.. now we're talking.
The W. Mission Bay bridge will have plenty of clearance if you want to venture out towards the ocean. From the bridge, past Quivera Basin(where I keep my Cat 27, it's about a quarter mile south then 1 mile due west into the pacific. So that means you get to tack out to the big water, with a leisurely down wind run back to Santa Clara Pt.
Disclaimer: it's been many years since I sailed out of Santa Clara Pt... always on boats under 20 ft. You'll have to thread your way through Mission Beach... down Mission Blvd to get to Santa Clara Pt. It can be a navigational challenge for the unfamiliar. but worth the effort. There are larger ramps, mainly used by power boats at Dana Landing... and South Shore... Dana Landing is easy to reach as you exit I-8, cross the bridge, stay on Ingraham St, turn left at first stop light to enter facility. I don't recommend South Shore, it's too far to the sailing area unless you like to motor, and there's a bridge (38 ft clr).. If you choose Santa Clara Pt. take the W. Mission Bay exit (stay in right lane) follow to Mission Blvd (big roller coaster) turn north (right) about a mile up... there's a light. Just be careful of pedestrians, cyclists, etc... because it's like an alley way to get into the parking area. It's very cool there.
There is a commercial boat rental facility on the north end of Santa Clara Pt... The MBAC is on the south side, where the ramp is.
Mission Bay Aquatic center is managed by San Diego State and UCSD... public can take classes for an increased fee, alumni (like me) and locals, a lesser fee, and Students, including J.C. students pay very little. They have a great Sailing program, plus water skiing, surfing, crew, windsurfing, etc. I learned to water ski there when I was in my late 40's... then just signed up for weekly sessions... Very cool, just show up, pick out the ski you want to use, rent a wetsuit if needed... hang out on the beach in front of your car... (there's also an advanced program with a slalom course and a jump ramp)... 3 hr sessions are in the morning when it's glassy.... go have lunch. Then sail in the afternoon when the sea breeze fills in. I spent many, many enjoyable days doing just that. I also brought my along surfboard for additional options.
Okay, I kinda rambled on there... sorry.... but I have so many memories of that time and area I can't help it. Good Luck, have fun.. any other questions, send be a private message.