First, congratulations on your new puppy! Oh, and thanks for formatting your post so well; it was a much easier and more structured read than some of the never ending walls of text we see around here.

Do I leave him in the kitchen all the time?

I highly recommend that people confine their puppy to a small area in order to set them up to have good habits, because good habits are just as hard to break as bad habits. One of the most important things you can do at his age is set him up to succeed by confining him to a small area (whether that be a crate, exercise pen, or room closed off by a baby gate) that has appropriate items to chew and taking him hourly to the appropriate place to pee, rather than providing him too much freedom too soon- only to find that he has chewed up your shoes or peed on your couch. Personally, I think investing in an exercise pen or crate would be a much better idea than the kitchen.

If I leave him in the kitchen all the time, how does he get exercise?

On the Potty Pad I was using the two items rule I use with my cats' litter box: if they use it twice, then I should change it.

I'll try to answer both of these as one.

Did your vet confirm that the risk of contracting parvo in your area is that serious? Usually veterinarians are much more concerned with the health and safety of a puppy (with good reason) than they are with training or socialization- but this often causes them to blow the risk of parvo out of proportion. It's completely understandable if your area is at a much higher risk than others, but as a result it will cause some set-backs with his house training and socialization.

Assuming that you can't take him outside until he has received his second round of vaccinations (here is a timeline of the vaccines that he will need just to ensure that we are on the same page), then now is the time to set a substrate and spatial preference to make the transition to peeing/pooping outside as easy as possible. Ideally, you'll want to use a potty pad that is as similar as possible to the final substrate (grass) that he will use one he is old enough, so you may want to consider investing in something like this (you can also make your own using a roll of grass and a cat litter box). Puppies want to pee where they smell pee but not where they smell poop, so clean up all feces and replace the substrate every few days. In addition to preventing your home from absolutely reeking, you'll also want to create a spatial preference by placing the potty pad outside on your balcony or similar area that is as far away as possible from his confinement area (crate, exercise pen, etc.).

Every hour, put him on leash and run him (you don't want to have any accidents along the way) from his crate/exercise pen out onto the balcony where his potty pad is. Stand still, wait for him to potty, and once he pees and poops don't forget to reward him ('Good boy' and a treat)! Now that his bladder is completely empty, he can have ten to fifteen minutes of safe play time (fetch, tug, etc.) without risking any accidents- before going back into his crate/exercise pen/room.

... and repeat every hour.

Again, the most important thing to take away is that the best option, by far, is just to take him outside (considering that the risk of parvo isn't greater than in any other area), as he will be missing out on so much crucial socialization. You'll have a lot of catching up to do once he receives his second round of vaccinations, so here are two really great videos, Part 1 Part 2 on making up that lost opportunity for socialization.

I hope this helps!