Type in "digital painting" into Youtube.com search. Watch a few videos on how other people paint in Photoshop. Photoshop is just a tool. If you have can't draw in real life, you will not be able to draw in Photoshop. You need to learn drawing basics before you can draw realistically.
If you haven't already done so, book yourself into a life drawing class or two.
It is more fun to talk with someone who doesn't use long, difficult words but rather short, easy words like "What about lunch?"– Winnie the Pooh