But we don't really want to deal with any severe restrictions or COVID Passports, or lockdowns, or ridiculous outdoor mask mandates or any other stupid bullshit.
How bad is it in CA? I heard San Diego was fairly open. Are attractions closed? OR is it open and worth visiting?

I've been there before... but not during COVID obviously.

Also, do I have to leave my Glock 19 at home? I have a 10 round magazine for it, because IIRC, CA has a 10 round mag limit.... or has that been struck down yet? I'm half of the mind to leave it at home, because I can't carry it anyway, and we'll only be able to have it available when in our hotel...

It's bad.  It's really, really bad.  Weather is cool, May Gray/June gloom. 40 million homeless living on the streets.  Hundreds of miles of desert to cross to get to the populated coastal strip.  Almost nobody wears a cowboy hat.

OTOH, almost everything is open.  Some capacity restrictions. Lots of outside dining.  Take out alcohol (drink at home, not in public or in the car) Check ahead if you have something specific in mind because reservations might be required.  The governor is trying to make people think we didn't live through his mess.  Expect to wear a mask.  Fill up before crossing the river.  Wear a belt in case your pants won't stay up without a pistol in the waistband.

I was just in San Diego this past weekend.  Weather was great, everything is open as far as what I saw, I don't know about any particular attractions.  You don't have to wear a mask on the street.  Some restaurants have reduced indoor seating, some don't it looked like to me, or the owners didn't give a shit.