Do get the puppy vaccinated on schedule, feed it the best food you can, keep it clean and well protected, and isolate it from dogs and areas that are likely to have disease exposure such as parks and animal shelters and pet shops where many animals come and go. Use good hygiene and nutrition to maximize your puppy's ability to mount an adequate immune response.
Check out the obedience school. Is it clean? Really, really squeaky smell good clean? How often is it disinfected? Very important: Are they very insistent about seeing proof that your pup is current in its vaccination schedule? If they take your word for it, they take everyone's word for it!
Odds are, if you're careful, you will have a great experience, and a healthy, well-adjusted canine companion with minimal effort. Can things go wrong despite perfect planning? Sure. But the bet is a good one. Extreme overprotection or lack of any protection are asking for trouble.
It's your puppy. You decide.