I did a reinstall of WordPress on the server, tried the “pretty links” and that didn’t work… so went with the “ugly” permalinks (I had the message “If your .htaccess file were writable, we could do this automatically, but it isn’t…” on the original install, when I did the reinstall it wasn’t there anymore).
Today I tried “pretty links” again, and it seems to work? Not sure how that ended up happening, but hopefully the change is permanent.
Also, this page is juuuuust gibberish, https://codex.wordpress.org/htaccess and talks about it, but not how to edit it.