Remember to play. There are multiple terminal emulators, window managers, shells, all the things! Try 'em out. When installing stuff to test via distro package, keep note of which dependencies were dragged in so you can get rid if all of them, not just the thing you wanted to test. Also keep a list of what you tested and later got rid of (and why) so you avoid testing it again.
If you ever ssh into other machines to do stuff, learn the minimum of vi (classic w/no arrow keys, not vim) and bash. Servers “always” have those (though FreeBSD also has tcsh).