There's a ton of people in the San Diego area. The only local law that you may encounter is that OC in Oceanside is unlawful. However that law is unenforceable and people OC in Oceanside these days without incident. The main thing you need to be aware of is the K-12 schools. Take a look at the information californiaopencarry.org, watch pullnshoot25's videos on youtube, read the forums for a while, and consider meeting up with some seasoned UOCers who you can ask questions of before you venture out alone.