how to combine photos to create a chess board

You should shoot the board empty and the pieces on a background that  you can select and delete. Then you add shadows and save them as png files. You need  front side and backside shots. It would not be a fair battle  attacking from behind.   All can not be Queens it would be too bloody lots of scratching and biting,  When you place in the pieces use the place transform to scale the object for the right prospective.

Start from the back pieces and work forward. Use on image as the board then as you add the other layers (File >Place Embedded), you will need to select then mask each "piece" and build up the pieces in layers. Once you have that , you will need to paint in shadows, where the shadow of one piece would fall on another. Do that with a layer set to multiply blend mode and a black brush set to low opacity (20-30%)

Dave

Please post some examples of end product or its parts to be able to understand what is actual task.

Into one what? Chesspiece? Chessboard? Image? What subject matter did you use to simulate lifesize pices.  We are in a dark place its hard to see what you see and want to do.