Some tmux shortcuts you should know

Meta key: Whether CTRLA or sometimes CTRLB

tmux detach: CTRLA + D
tmux list sessions: tmux ls
tmux reattach: tmux att -t <session id>
tmux create window: CTRLA + C
tmux change window: CTRLA + 0-9 oder CTRL + /
tmux kill window: CTRLA + K
tmux split horizontal: CTRLA + +
tmux split vertikal: CTRLA + _
tmux change pane: CTRLA +
tmux kill pane: CTRLA + X
tmux find in windows/panes: CTRLA + F
tmux align panes vertically: CTRLA + ALT2
tmux align panes horizontally: CTRLA + ALT1

tmux help: CTRLA + ?
tmux console: CTRLA + :

Extra: Great window managers for tmux lovers

https://awesome.naquadah.org/
https://i3wm.org/
https://swaywm.org (uses Wayland instead of X11, features similar to i3-gaps!)