Photoshop skill session 1: Earth and eye

On this first skill session we learnt how to;
1-Open a photoshop file so we can have the right size, save file name and lots more.
2-We learnt how to insert an image onto photoshop.
-There are two main ways to do this, on one of them I had to select the picture then press cmd apple + C  [copy] and then reselect photoshop then press cmd apple + V  [paste].
-I also can drag the photos from the desk top on to one of the layers.
3-The oval marquee tool lets you select an area to delete then if you inverse you will be able to delete the outer part of the picture.
4-The magic wand tool cleans up any left overs which you don't want and it will have to be in the same colour tone.