This is in addition to what you paid for that puppy, remember. If you adopted from a shelter, the shots may be included in the adoption fee. But you still need to have a vet checkup if for no other reason than to find a good vet for your dog and 'introduce' the two of them to each other. Almost every dog that comes through an ethical rescue group is required to be spayed or neutered, or already comes that way. Some local veterinary clinics offer spaying and neutering at very low costs.
Some breeders suggest keeping the puppy on puppy food for the first year of their life.
The higher quality foods will be more expensive, but food is one place you should not try to cut corners on your expenses. Start saving now for these items as they can't wait for a few weeks or the next paycheck after you buy the puppy. Bowls - I recommend the steel ones because of the problems with Pug pimples and because they're easy to throw in the dishwasher. Most pet stores carry them - make sure you get the ones large enough for the full grown Pug head to fit into. Crate - even if you don't use a crate for house training, you'll need a crate to transport your dog.