Don’t jump ahead and try to install Rock until you get all your bios settings correct. Now that you can access Bios reset Bios to defalt (F9) if you haven’t already done that. Make sure you save and exit (F10) Then go back into Bios and finish. Make sure UEFI is unchecked and the Legacy is checked. Some of the bios settings are in the Advanced tab BOOT CONFIGURATION Make sure network boot is disabled under the BOOT DEVICES tab. make sure USB is checked. Under the UEFI BOOT uncheck FAST BOOT. Make sure you save and exit. Are you still not seeing your SSD?