You can do it from blender. Just need to be able to use pshop or gimp a bit. Render and scene (use the renderer you like from blender, like eeve or cycles, learn a bit on how to use them there are many tuts).
When you have your rendering alone, you can export PNGS with alpha form the render windows, open in pshop and put the background in the back and the model in front... this is the easy way but you will need to resize models etc...
The other way is to use planes inside blender for the background photos to be rendered, but I should try the first method as is easier.
Regards.