`less` - page through text one screen at a time

less [-F] [-N] [file]

Options you will use

-F: Quit immediately if the whole file fits on one screen.
-N: Show line numbers.
-S: Chop long lines instead of wrapping.

Gotchas

Keys: space/f forward, b back, j/k line at a time, g top, G bottom, /pattern search, n next match, q quit.

Try less in a real terminal Free, in your browser - a real Ubuntu terminal to try it in, with missions that check your work.