Puppies really need a lot of engagement and socialisation - its not a toy, and walks are important, they get your dog used to the environment around them and to get to know other dogs and humans, which is important, especially for breeds that get kinda attached to their owners, like pitties.
A dog is an investment in time and energy especially in the early days. A tired, well played with puppy is a good puppy, they're less likely to chew up your home (this is important!) and be socially well adjusted. Leaving your dog alone is a sure way to end up with a poor dear who has no idea what to do (just like with people! You wouldn't leave a baby all alone for 2 years right?).
You don't have to give up your dog though. I know people walk their dogs at night after work. I used to wake up early (back when my dog was younger and didn't mind walking up early) to walk him - before dawn.
Having a dog means adjustment. Walking your dog every 2 months essentially means your dog's deprived of a good chunk of its childhood.
Its also worth considering, if you don't have time to walk your dog, you'd want to see how much quality play time you have with the dog. It might be worth asking around if there's folks in your family willing to help or working out a schedule that works. AT LEAST daily walks - 2's probably better. Being able to socialise with people and other dogs is also essential. Your dog isn't going to get this with bimonthly walks.