>>9043840socal here. imo the best flea/swaps are ran by mexicans who tend to pile random loose, non-happy meal, action figures onto a table or box, for chump change. These are only open on weekends, and usually charge a buck to get in. But there are still the bootleg minifigs, common fad gifts like fidget poppers and those reversible octoplushes, etc. Memorable finds are D-Real Growlmon and the Mega Man Air Raider
then there are the monthly (every 3rd sunday or something) ones. these are ran by common americans with their old furniture, antique vinyl records, handcrafted etcs, and other wood/tin memorabilia. Rarely you'll see toys on a table, and mostly boxed toys for scalper price. I have found a few nice finds, like a Neca Big Daddy and DKC cartoon toys, but these places aren't a usual rounds for me.
Then there are the INDOOR swap meets. Go to one if you're nearby out of curiosity, but those are boring as fuck because they're really just plain old stores offering common services and bootleg/wholesale items.
But just so you know, a swap meet these days (if not before) isn't always about finding what you're looking for or discovering something you forgot about. it's the experience of being there and discovering things you didnt know existed. There should be little to no shame/regret in bringing home nothing after traveling far