So far, I've run into two or four problems.
First: I'm doing it on a Chromebook without a read/write screw (Lenovo C340-11). This means that in order to disable read-only protection, I have to disconnect the battery. And keep it disconnected. Very unsustainable, especially for what's supposed to be portable.
Second: The disk is already partitioned quite a few times, all into a bunch of 512-MB boxes meant for storing Chrome data. Is there a way to erase those?
(Third: I can't follow the DistroTube tutorial exactly - it wants me to partition the disk a bit; when trying, I get the error that the disk I'm trying to partition is in use. Not sure how much of a problem this is, because Arch wiki doesn't even list that step as a thing I should be doing.)
(Fourth: I don't know how to actually "install" it in a way I can boot from - every time I reboot, I need the USB + need to redo all progress such as wifi. But I'm feeling like that's a later step?)