Pleasanton is pretty well located as far as rocketry goes.
First and foremost, you'll just be a hop/skip/jump from the LUNAR (the Livermore Unit of the NAR). Fall/winter/spring launches on Snow Ranch (about 30 miles east of Stockton) ranging from LPR up to HPR. Summer launches at Moffett field near Sunnyvale.
Secondly, you'll be able to attend Tripoli Central California (TCC) launches in/around Helm (about 30 miles west of Fresno). They hold monthly launches almost year round and the two biggies are Dairy Aire in May and October Skies in October (of course).
Thirdly, you'll be about 30 minutes from Stockton which is the home of Jack Garibaldi's What's Up Hobbies. You can save shipping charges by picking up your goodies directly from Jack. Be sure to call ahead.
There's still a lot of confusion about the Cal Pyro III license to legally launch composite motors but I've seen no changes in how launches are run. Then again, I'm not involved in the process. I just pay my launch fees and have fun. My opinion is that the State laws were written to cover the commercial fireworks industry and hobby rocketeers were just lumped in as a matter of convenience or as an afterthought. The Cal Pyro III license costs $87 and is good for the three years. There is a short L2 like exam that is given only in Sacramento or Los Angeles. The big deal is that you must present letters of recommendation from five CalPyro III license holders who have had their licenses for at least one year. As more rocketeers obtain these licenses that should be less of a problem. Oddly enough, California law doesn't really care if you have a NAR or Tripoli cert to launch high power rockets. What we call garden variety HPR, California law calls "Extreme High Power Rocketry.
Park flying is another matter. I don't do it. In theory, you're required to have written permission from the property owner and the local fire marshal is supposed to approve your launch. How this works in the real world, I don't know. I see kids with Estes starter kits at the park often enough that I think they will be okay. Not so sure that an adult would get the same no-issue treatment. A local private citizen with a small airport allows 4H groups and others to launch LP and MP rockets on his property in addition to a couple of RC flying clubs. Although I have launched there with various groups, I have never met the property owner in person so I have no knowledge of his arrangements. Group members just shrugged when I asked about it. I guess that in that county, rocketry isn't a big issue for the local authorities.
Depending on when you make the move back to Cali, plan to attend the next big LUNAR launch in either October or November at Snow Ranch. There are a fair number of TRF members there and I'll stop by and say hello.