Internal HDD has F: (storage) and a partition for Ubuntu, which is the A: drive in Windows and /dev/sda3 in Linux.
I was originally hoping to do it this way and be able to dual boot them, but the more I think about it the more I feel that just going straight to Linux and biting the bullet would be better in the long run, and I can flash Windows if I really need it.
I was trying to get GRUB to act as boot loader but for the longest time I couldn't even get GRUB running, even with at least 5 different troubleshooting ideas. Then once it was running, I still couldn't get it to mount the EFI. Then I started getting the boot loop issues and Windows OS stopped working, but I figured out how to get Linux desktop running via shimx64.efi in the BIOS boot loader.
This computer is natively a Win 10 machine, and I was trying to add Linux to it.