Check the specs on your MacBook to confirm if it is a 32-bit CPU and 32-bit EFI. Most distros are now 64-bit in both which won’t work on 32-bit architecture. In the link that @phungus provided, I was dealing with a 64-bit CPU and 32-bit EFI which makes the installation trickier. If you are 32-bit across the board, find the appropriate 32-bit Linux Mint install and go for it.