So, I downloaded the emulator but can't get them to open. How do I do this? I tried opening with 7zip but that made it worse.

These forums aren’t the place to get help with ROMs or emulation.

But if you can’t properly extract your emulator from a compressed archive then you probably didn’t downloaded a very good/secure emulator.

I'd recommend joining the community on Discord: https://discord.gg/CgQER9G

There's a #tech-support channel there where someone will be able to help you get setup!