How do I enroll the liquorix kernel? I can't seem to find it anywhere. Or the default kernel for that matter.

generally you need to put your bios into secure boot "setup mode", this changes based on bios but generally requires wiping any keys already enrolled. once you are in setup mode you can boot into your install. depending on your distro you can then sign your kernel+modules and update the tpm. arch wiki has a good guide. also beware each time you update your kernel you need to resign kernel and modules otherwise you won't be able to boot