Photoshop Assignment Follow-up

I think the biggest problem I had with the Photoshop Assignment was trying to use the program on my housemate's Mac. I am used to a PC and I currently do not have Photoshop on my computer so trying to use a new program on a new system definitely presented a challenge. There are a number of things I would change about my image if I was more familiar with both.
Instead of simply placing the pictures around each other I would much rather create one picture that incorporates all of the smaller images. My housemate tried to teach me to feather and use some of the other basic controls however I had more issues trying to find what layer I was on and just be able to move the single images without deleting them entirely and replacing them.
I have used photoshop before but in a very limited setting for my high school's yearbook. In that situation I was working with one picture and not doing much more than inverting it occasionally or cropping out elements. If I could just spend enough time exploring Photoshop I think I could regain a better feel for it.