Hello @doughyi8u
Gentoo live-cd can't boot in UEFI mode...
I suggest you to use SystemrescrueCd (GNU/Linux distribution based on gentoo),, and you can download iso image from here
http://www.system-rescue-cd.org/Download/
1-download iso file
2-install it on USB stick
3-disable secure-mode and enable UEFI mode in bios
And you will boot on UEFI
Best Regards
sai