Rome is an encyclopaedia of historical monuments, you can see them everywhere and moreover you can learn many details about everything you see.
Unfortunately I only got to visit part of the Vatican, I didn't visit the Vatican Museums and the Sistine Chapel, I arrived at the Vatican around 10 am and the queue to visit the Vatican Museums was over 1 kilometer long and honestly I didn't have the patience to stand in line for more than 2 hours (it was too long).
I hope that in the future I will have the opportunity to visit other Italian cities, so far I have visited Venice, Mestre, Treviso and Rome.
I wish you that your plan to visit Rome comes true as soon as possible.