screen is the OG. tmux is the modern take on it. Regardless of your choose, you will rock the terminal. Also see: byobu.
screen -R session-name # Start or resume a session
screen -list # List the screen sessions (and show which is Attached)
Ctrl-a, :command # Try the "help" command
Ctrl-a, S # Split the pane horizontally
Ctrl-a, Tab # Switch panes
Ctrl-a, n or Ctrl-a, p # Next and previous panes
Ctrl-a, c # Create a new window in the current split (Start a shell in the pane)
Ctrl-a, " # or "windowlist"
Ctrl-a, X # close pane
Ctrl-a, A # Set a name (window title) for the pane
Ctrl-a, | # Split the pane vertically or "split -v", not supported in the screen bundled with MacOS (old version)
# Maximize current window, resize to equal division
bindkey ^O resize max
bindkey ^P resize =