nano is a simple beginner-friendly editor. All shortcuts are shown at the bottom of the screen. Ctrl+O saves, Ctrl+X exits, Ctrl+W searches. It is the easiest editor for quick config edits on remote servers.
nano — Beginner-friendly Editor
nano file.txt
# Shortcuts (^ = Ctrl)
^O # save
^X # exit
^K # cut line
^U # paste
^W # search
^G # help
# nano is shown at the bottom — no modes to learn