You might want to start by visiting L’Aquila and then heading down toward Pescara, Gargano Peninsula and Bari on the Adriatic. One wonderful contributor to the forum regaled us with updates on a 4 month trip. The end of his post describes a stay in the Salentina Peninsula in the “heel of the boot.” I’m sure if you send him a PM with questions that he would reply with first hand knowledge.
As far as Pompeii goes, its pretty straightforward and inexpensive on how to get to Naples and then Pompeii by train. The Archeological Museum in Naples houses the artifacts excavated at the site. If you are interested in Pompeii, don’t miss the museum. The train from Roma Termini takes an hour and 10 minutes to get to Naples. It’s a short walk to the Circumvesuviana that takes about 40 minutes to Pompeii Scavi. When you get to the ruins, they’ll give you a booklet in English as a guide. Rick Steves Audio Europe app has an excellent audio tour of the site (free!).
If you want guided tours of the museum or the site, check out highly recommended Mondo Tours. They offer reasonably priced small group tours of both.