Target currently has stock of the PS5. You need to get it shipped to your local store. Links can be found below.
Stock looks to be differing based on where you’re located, so it won’t be available everywhere (it looks to depend on stock per state), so hopefully you can grab one.
Amazon will likely go live at some point throughout this week. You can find the links for both consoles below and you’d be wise to keep an eye on them.