USB BOOTABLE OS hard drive NOT WORKING

Hello all- to make this some what short I’ve posted on here a while ago ( Flashing? Folder Tried everything)

Basically got a used iMac and figured I could fix it up and either resell or keep it around as a back up. I was getting a flashing fold which was my previous post. A lot of people recommend a bootable usb.

I ordered lion off eBay and managed to figure out to get snow leopard onto a usb myself.

I will turn on the computer and hold down the option key to see the 2 hard drives both (snow leopard and lion) if I select lion it will load with an apple logo sit there with the spinning loader and then go to a crossed out circle and still continuously load forever ( like it’s stuck).

When I try SL ( because I found someone online saying the crossed out icon during lion install means it can’t handle that OS I tried to install aka lion) it will load and then I get lines across my screen like the whole system froze. I’ve tried every and all things and I’m at a loss. I’m pretty tech savvy, but my gut is telling me I might have to buy and install a new SSD hard drive. if I have to go this route please advice what I should install if I want to keep this computer up to date with current max OS aka Catalina Big Sur etc.

Side note : I managed to install a OS version of Catalina onto my portable hard drive - had to do this to install snow leopard with disk maker x ( didn’t work- found another program through Linux to do it), my thought is I’m gonna try to plug this into the iMac and load up the OS onto the iMac and try a back door approach in theory I don’t know if it will work- but keep in mind the “Macintosh HD” isn’t showing up when I hold down option. This was before internet recovery so I can’t just install with a physical disk or bot table hard drive- just won’t read or recognize it.

Any thoughts are appreciated. I uploaded photos for reference.

Thanks!