how di i add a picture on oly one face of an object
Go to ‘uv face select mode’, select the face you want, and then go to UV image editor. Load the image you want and then go to ‘vertex paint’ mode
and in the 3d window hit Shift+K. In ‘texture’ mode you should see the texture.
I hope it helps.
(if it is too confusing,hereis a tutorial on texturing)