Welcome.
Check if your machine's model is listed here:
https://wiki.galliumos.org/Hardware_Compatibility
I'm not an expert by any means but just liberated two Chromebooks. You'll have to set your Chromebook to boot to developer mode and then update the firmware then you can install from the USB drive. The updating of the firmware will require removing the right screw from
inside the case. Then run the unauthenticated script:
https://mrchromebox.tech/#fwscript
However, search around on the web for articles to get an idea of the process. Basically once the machine is properly prepared, it looks like you can boot any x86_64 distro from USB.