Am I allowed to take photographs from a video game which i create the still shot for myself, and then print and sell them for profit?
The short answer is: no.
You almost certainly are not permitted to do this. Your right to use the copyright content of the game (which will include screenshots showing in-game assets) will usually be set out in a EULA or another form of licence agreement. This will almost invariable prohibit resale of that copyright content.