The editor is pretty much identical between mac and windows, except that on a mac you would use the command key when a keystoke calls for CTRL and the Option key for Alt.
Do you have a photo open when you go to the cookie cutter? You basically just click and drag over your photo to draw the crop shape. Are you sure you are using the cookie cutter and not the custom shape tool?
I don't remember what the directions were yesterday, when I was experimenting with Photoshop, but I believe that the directions told me to use the custom shape tool, but I couldn't find it. It said to click on the rectangle, and a menu would come up, but no menu came up. So I thought I would just experiment and click on 'cookie cutter' and see what would happen when I clicked on it. I tried using some keyboard shortcuts to see what would happen (just trying to figure out how to get something to work) and at the web site for Photoshop for Mac, it said to click 'Q' (I can remember what was supposed to happen), but I clicked 'Command' and 'Q' at the same time and it closed the program! The web site didn't say which other key to use with the Q, and nothing happened when I just clicked the Q. Another thing I was trying to do was to make something in Photoshop (this was on another web site) and I had to go to 'window' then the next step was to go to 'channel' and click it on. I went to window and there was no 'channel' in the drop down menu. There were other options, but no 'channel'.
Okay, first of all, if you want to learn PSE, I'd suggest you stop looking at tutorials for full photoshop till you know your way a little more. There are no channels in PSE.
What you are reading is evidently a much more complicated way to do what the cookie cutter does in PSE(it's not in PS). Just click here:
and then follow the directions in my previous post.