Was this explained in the tutorial? I missed it if so. I just recall the first time I mis-clicked on a move card and couldn't cancel out I had a relatively rude surprise and was disappointed. (I find going backsies on the current action something I do a lot in TRPGs, is all...)
Choose a Move card. Click on the square where you're ALREADY standing. Notice the handy-dandy new UI that pops up (some yellow arrows) asking you to select your facing. Select. Celebrate!