You will need to carry your own luggage between the airports. Limousine bus is the most convenient for you, but it willt get you to HND a couple of hours earlier than you need to be there.

You don't have a heck of a lot of time for sightseeing in Tokyo, but if you wanted to do it, you could take a train to Ueno, Tokyo, or Shinagawa, then leave your things in a locker for an hour or two before continuing onward to HND. Out of the available options, Shinagawa is probably the least interesting to look around, but the simplest, since you can take the Narita Express from NRT to Shinagawa and a Keikyu airport train from Shinagawa (Keikyu station) to HND.