As Renard stated above, burn using Etcher. Etcher will validate if the USB burn matches the ISO. Also re-download the ISO and verify checksum. Kinda sounds like a bad burn, and this is the place I would start with troubleshooting any new install. Sounds like you have UEFI and secureboot off. Also might want to check what USB port you are using, sometimes there will be one that is for UEFI only, usually it will be a different color.
AMD drivers should be baked in the kernel, so I'm not thinking that's the issue. Even with Nvidia, Solus is the most friendly distro for it that I've found. I run Nvidia cards on all my PC's and have never had an issue with getting it going. The Nouveau drivers work fine on the live USB and on first boot, then after doing updates, DoFlicky (the driver manager) will handle the Nvidia install (including the 32bit libraries needed for Steam). Very easy to do without having to cut and paste anything in the terminal. Unsure why no other distro does this...