Step by step instructions to install Zorin OS wanted

No worries! Yeah, copying the .ISO files I've found most recent to be the fastest for USB bootables.

UEFI just replaced the older MBR style booting. Also SecureBoot for most newer ones so, have to disable that in BIOS, and Fast Startup in power options in Windows. Check out the Before you install post, has good info on both SecureBoot and Fast startup!