If you have Zorin on a USB drive and cannot boot into it (assuming you changed boot order), you may want to check a few things:
- Verify your Zorin download: Methods of downloading Zorin OS
- Confirm that the USB drive is working properly, including any cables used to connect to the drive. Use another computer or USB drive, if you can.
- Disable Secure Boot: https://www.appgeeker.com/recovery/disable-uefi-secure-boot-in-windows-10.html
- Disable Fast Startup: https://winbuzzer.com/2020/05/19/how-to-disable-windows-10-fast-startup-hiberboot-hybrid-boot-hybrid-shutdown-xcxwbt/