I hope that you enjoy Japan. I enjoyed my trip there very much. If you are moving around Tokyo, I would recommend getting a daily pass for subways instead of buying as you go (but, keep in mind that many lines are independently owned and require separate passes). The
Takanawa Prince was a great place to stay; Shinigawa Station is just up the road for the Shinkansen and other lines. I look forward to visiting again some day.
Perhaps there are other questions that you could ask to help us give better advice. Cash is king. Bring lots.