,
Shortcut Command
Ctrl-q c Create new window
Ctrl-q i Create new pane horizontal
Ctrl-q / Create new pane vertical
Ctrl-q ? List shortcuts
F1 Goto left window
F2 Goto right window
Ctrl-q b Select window from list
Alt-⇑ Move cursor to top pane
Alt-⇓ Move cursor to bottom pane
Alt-⇐ Move cursor to left pane
Alt-⇒ Move cursor to right pane

If you want to know all the shortcuts visit the tmux configuration file ~/.tmux.conf

If you want to master tmux RTFM :

man tmux