NOW! You can't start too soon (must make sure you take him to safe places until he has all of his shots). Socialization is extremely important in this breed. Get him out out out. You will thank yourself for it when he's grown!
And congrats, how about some pics of the little guy?
I would work on engagement, recall and focus...puppy classes for socialization are wonderful. This video shows how to make it fun and rewarding with food/markers. YouTube - RoniTristar's Channel
I would also look at Leerburgs site~ Michael Ellis clips for fun methods of engagement. Leerburg Streaming Video
Puppy classes, socialization and BONDING is most important with a puppy. "Formal' obedience isn't so much the goal. Your mental picture should be of a joyful happy puppy who doesn't even realize they are being 'trained'!