To take a screenshot on the Alcatel One Touch Pop Icon, press & hold the power button and volume-down button at the same time.
You can view your screenshots via the Gallery. There will be a separate folder in there for screenshots, once you have taken one.
If you want to copy your screenshots to your computer, be aware that screenshots are stored in a different location than the regular photos you take using your phone. When your phone is connected to your computer, first go to the "Pictures" folder. Then, inside that folder is the "Screenshots folder". (Regular photos are located in the "Camera" folder, which is located inside the "DCIM" folder).
Cheers!