These tutorials aren't covering the fundamentals of Photoshop, but they are quick fun ones that will help build up your toolbox of skills. Some of this stuff will be completely new, and you might not understand it, but just roll with it. It's amazing how much you can pickup just following along.
Complete as many as you can.
Can you access an image of yourself? Why not try this tutorial on your own photo? If you do, press (Ctrl+Shift+U) to make it B/W. Then get a black paint brush and paint out the background. Apply the rest of the tutorial from there to your image.
Can you make your own? This photo was taken by having a bright light behind the person, so their face becomes dark and silhouette. You could try and take your own (just ask the teacher first) on a blank background, open it in photoshop and press (Ctrl+shit+U) to remove all the colour. Press (Ctrl+L) to open Levels and move the sliders till it goes darker.
This one is more challenging. You will need to go and find a similar photo. Check this link for images that you could use.
Finished? Here's your reward, the talented and very funny James Fridman. He is masterful with Photoshop!