My absolute favorite is nnn (mine's aliased from "n3", is that insane) -> "r" which gives you a vim console for renaming all the contents of a directory. Beats perl-rename and everything else cause it's actually interactive. Although it is possible to write files over each other with it, so gotta be careful.

In the default view you literally just use the arrow keys to navigate, basically the same as the old Windows tree explorer or whatever else like that. 1/2/3/4 flip between tabs. If you hit "right" on a file I think it hits xdg-open or something to open it in the default program. "e" opens text in your ... default EDITOR? Guessing. "?" for help and a lot of other commands.