I use the shortcut w to move the cursor one word right. Is there a shortcut to move a word left?
It's b.
You can see other motions here:
Vim documentation: motion, 4. Word motions
Generally a Vim command consists of:
count action motion
Where:
count is number of times you want it to execute. The default is 1.
action is obviously an action: d for delete, c for change, default is empty, and it means simply move.
motion is the direction. You got that already.