Which Japan Rail Pass to buy?

I will be visiting Japan in summer and will be travelling mainly around Nagano, Kamakura, Tokyo and their surrounds. Which type of Japan Rail Pass should I be buying? I know there are different types of JR Rail Pass for different regions and it is all very confusing to me. I would like the JR Pass to cover my train ride from Narita Airport to Shinjuku too. Thanks for your help!

You can check the passes in this link and see which pass, if any, is best for your itinerary.

https://www.japan-guide.com/e/e2357.html

But perhaps JR East Nagano Niigata Area Pass is the closest to what you are looking for. It also covers Narita Express train.

https://www.japan-guide.com/e/e2361_nagano_niigata.html

Make sure if that pass pays off.

You need to make a more detailed plan (eg how many days , where) to be able to answer your question as all passes have some type of time restrictions additional to the range restrictions.
Then have a look here for the best pass/passes for your trip: https://www.japan-guide.com/e/e2357.html

But remember NO pass might be the best option as well. Ie just an IC card and single tickets for the trip to Nagano.

Enjoy your trip to Japan!