Shooting is available free of charge on a lot of federal public land in CA. Unlike your former or soon to be former environs. Not sure of the boundaries in the north and east San Diego County and Imperial County. Anza-Borrego State Park is a no-shoot area. A really big park. All the state parks are no shoot. Nominally no possess but I doubt too many people worry about that.
Almost all BLM land is available to shoot on, subject to restrictions on campgrounds, roads, etc.
Once you get east of I-15, it's a lot like Texas, desert, close to Mexico. Beaches are nicer. Surf fishing is generally for smaller fish than you see in the Gulf areas.
Before we allow you in we need to know your opinion on beans in chili, sour cream on too many kinds of Mexican food, and tacos. Oh, and we don't want to hear about how Texas BBQ is better than Santa Maria BBQ. You will however get points because at least Texas BBQ is beef and not pork.