Costco, because it has everything I'd need. In bulk.

Sounds like you'd enjoy the TV series "Naked and Afraid". Usually there's a pair trying to survive with only one piece of survival gear and no clothing, so a bit more extreme than solo. But I do remember one episode where the guy said "Running water with bubbles means it's safe!" and then got a horrible parasitic infection from drinking it which left the woman trying to survive by herself for a few days.

Inside the earths mantle, so I would die instantly. There’s a couple different TV shows that show that even the most confident and capable survivalists won’t last very long in the wild. Even if I had that hubris, I still wouldn’t want to be alone.

No ID also?

Probably something like a Scandinavian country with a good social safety net. It might be tough to get citizenship, but at least I might have a chance to survive that long.

a non-perishable food warehouse.

The inside of my apartment. My stuff is already there and the lease is signed.

Definetly somewhere in warm place simultaneously near forest and some running water source.

Exactly where I am at right now. I'm pretty frugal; started out with nothing and I still have most of it left.

This is just a guess, but probably somewhere in the Caribbean.

If you can get along a beach, you could probably wander around and find places to sleep when needed, and scavenge for food. Tourists love to spend too much on "local crafts" so if you could get halfway decent at weaving palms or carving coconuts, you might be able to kick off a career.

Downtown Toronto. I already live here, I'm mostly solo, I'm already broke, I'm already surviving. This game is easy.

The Ozarks.

I know the environment, the predators, the prey, all of it very well.

it would give me the best chance for survival. shelter is abundant. food is abundant. water is abundant. can't ask for more.

I'm with Costco guy. Minus humanity, or human artifacts, I'd probably go for Hawaii. The lack of predators would make the isolation and limited resources survivable.

Can I have a gun?

A friend's farm. A family member of his went through a survivalist phase, so there are bulk supplies there, plus a spring-fed water source. I'd just have to fight off my friend's other friends - we all know it's a good spot.

i think climate would be one of the the biggest & obvious un-modifiable factor.
if solo camping, then somewhere warm but not prone to extreme deadly heat spikes.
assuming the west is undeveloped and rugged, then probably that. (based on the premise that the eastern half is overcrowded AND thats a bad thing(?))
i would try to hit exurbs but be nearby civilization. else.. just be inside a city or near a friendly town.
its extremely complicated to forsee from an armchair. would require testing,optionality, and careful decisionmaking(and research&valid+complete_data), plus low-stake trial&error(also risk assesment, risk mitigation, safety procedures).

like as the world is now or some kind of post apocalypse? EDITED - saw the naked an afraid comment. when you say nothing do you literally mean you have nothing at all to start with?