I don't really get what you're saying..But,
IF you want to edit some pictures you gotta do few steps..
And about reading books, Books are good
But you can find anything on the web, they are millions of tutorials for all kind of designing softwares
and photoshop
1. Open Image : Ctrl + O / File > Open
2. Duplicate the background Image : Ctrl + J
3. Under the duplicated layer put a colored layer or a background
4. In the Duplicated layer, cut whatever you want, circle, rectangle [you'll be able to cut bodies and faces later] you need to train and learn the basics of cutting to be a pro cutter.
5. IF you cutted the part you want it to appear don't worry, click on ctrl+Z or ctlr+alt+z then ctrl+shift+I to invert selection now hit delete.
6.after you delete the unwanted parts of image you'll get the part you want with a background in the back
Layer mask is more advanced, find a tutorial for it.
This is the easiest way..
I Hope that was helpful
contact me ASAP
Cya |