
No climbing or jumping off things, basically just playing in the garden, and you practicing lead walking thre too. A puppy under 6 months old doesn't need organised physical excersise, just what it chooses to do, for which the garden is enough. What it does of course need is a lot of new experiences. Take him out and about in the car, go and sit in the shopping precinct with him, where people will want to talk to him etc.
Once he has all his jabs take him to the park in the car, or take him out of the door and just walk him for 5 minutes. If you have a car then the park will allow him to meet other dogs and people, but no forced marches. You build up the formal walks gradually, but make as many socialisation opportunities as possible that don't involve too much walking!