California is not a gun friendly state so once you leave there things gun related will be better until you get to MA, NJ, NY and a few other east coast states. As said you need to look into one of the non-resident CCW's that are widely recognized. Utah is a good one as are Florida and Arizona and not that hard to get.
Each state has their own requirements for issuing a CCW either resident or non-resident and each will be recognized by different states. It depends where you plan to go or in my case where I will not go. www.handgunlaw.us
is a very good place to look for information and includes links to the states so you can check their laws.
What to carry? If it is something that will stay in your RV a shotgun with an18 1/2" to 20" barrel in either 12 or 20 gage is legal everywhere I am aware of, do your own research. I am also not aware of any permits needed for having a shotgun.
Something to carry on your person, this is where you would need a CCW. A good start for carrying a handgun is an NRA Basic Pistol class, this is geared toward new shooters and the instructor should furnish all ammunition and the firearms for the class. I shoot and carry both revolvers and semi-autos and compete with mostly a revolver. A revolver is pretty foolproof, load, pull trigger and it will go "BANG." A semi-auto can be less reliable and there is more of a learning curve with them. Nothing wrong with them but you need to spend more time getting familiar with how they work and what to do when they don't. Glock makes nice semi-autos in that they are normally very reliable out of the box as are Rugers. I personally would shoot at least a couple hundred rounds through any semi-auto including the self defence ammo you plan to carry. One more thing is not to get a handgun that is too small. Yes they are easily carried but are harder to shoot accurately and are more prone to malfunctions especially the calibers smaller than 9mm. Jim.