IMHO it depends on your pup. You can certainly teach him now. I always beleive in training a dog from the second it walks into your house ... these are the rules, boundaries, etc. You just might not be overly successful because of his age! He's a baby ... LOL ... and it might be a constant battle.
Kyleigh is freaking smart. I had sit, stay, wait, heel, come, down, leave it, drop it, on and off down pat by 6 months. The ONLY thing I couldn't get to work ... toilet paper. She was OBSESSED with TP until she was about a year old ... and then for some reason, that switch went off and she no longer card.
It might be a test of will power between you and the pup, or he might not care at all!
Marionís Zoo-Kyleigh, Raylan-cat, Echo-TAG,