From PlayStation Blog:

https://blog.playstation.com/2020/11/05/playstation-5-launch-day-ordering-update/

The only way to get one is to order on line.  So if you didn't get a chance to pre-order - sounds like you'll have to be Johnny on the spot with checking online to see what stores have them available in your area and place the order online before picking it up in store.

More info for ordering:

Following Sony's announcement earlier this morning that all PlayStation 5 launch day orders will be online-only, Walmart has released details about launch day availability for the PS5 on November 12 as well as the Xbox Series X/S on November 10.

Hopeful PS5 purchasers will have four different chances to snag the next-gen console next Thursday. The PS5 and PS5 Digital Edition will be available to purchase at Walmart.com at 12 PM, 3 PM, 6 PM, and 9 PM ET on November 12. As usual, expect stock to be extremely limited, especially as Walmart will be holding back units to have enough for each wave.

Meanwhile, those hoping to get their hands on the Xbox Series X and S will only have one chance to buy either console at Walmart on Tuesday. Walmart's online Xbox listings will restock at 12 PM ET on November 10, so you'll want to be ready at your computer then. For both the PS5 and Xbox, we suggest making sure your Walmart account and payment information is up to date beforehand to help the process go smoothly.

Well that will make the lines smaller on the stores with only preorder pickups, boooohooo covid.

Without Covid they probably also wouldn't be available, since nearly every electronics store has a webshop nowadays.

They would have some in store to generate lines to sell other stuff.

Good. I feel like people will be looking for any reason to riot that day.
"Mcdonald's didn't get my order right? LET'S BURN THIS CITY TO THE GROUND!"
*steals console and 4k tv*

The irony is this sounds plausible in the USA... 

In Brasil Burguer King made a promotion that if you gone with a broom to the drivethru on Halowen you would get a free burguer.... the lines were humongous and of course not everybody got one, you can imagine the chaos after.

Looks like a responsible policy during the pandemic. Actually, if there is the risk of riots and people turning pre-Neanderthal and even destroying the objects on sale trying to grab one, it could be a good policy even in normaL times.

Someone is going to have to do a University thesis into wtf is going on with people these days.  I know that there were always some anti-social idiots around, but it feels we've regressed beyond the "burn the witches" era (and they didn't have the science education we get now).  Maybe it's because all the people who remember WWII are dying off, and people don't appreciate what happens when it gets really bad?