Chromebooks run ChromeOS, not Android. ChromeOS is based on Gentoo, but heavily modified.
Review the Interwebs for MrChromebox. He makes a bios that some older Chromebooks can use to boot Linux. However, newer (and especially cheaper) Chromebooks are much harder or impossible to install Linux on. If it’s ARM, that will potentially be difficult. You’ll need the board name for his table to really know if you can do it.
It might be better to get a used laptop in a form/size that you like, then put Linux on it. Much higher chance of success.
I’d recommend getting a Chrome addon that lets you backup your ChromeOS image. I forget the name, but Google makes it. In the case you can’t get Linux installed and haven’t bricked the device, you should at least be able to get ChromeOS back.
I have Arch running on a 2015 era Toshiba Chromebook. The smaller keyboard plays hell with my mind/memory and dwm/vim keybindings.
Good luck.