Dear friend,
Thanks for contacting Top China Travel! We welcome your upcoming to Tibet, China.
Tibet has several popular tourists places, Lhasa, Shannan, Shigatse, Nyingchi, Nagqu, and beautiful attractions are: the Potala Palace, Barkhor Street, Sera Monastery in Lhasa, Mt. Everest , Everest Camp Base, Rongbuk Monastery in Shigatse, Yamdrok Lake in Shannan, Namtso Lake in Nagqu, etc.
For having a Tibet tour, you could arrange 4-8 days, according to how many places you want to visit.
Here i recommend you 2 Tibet tour for reference:
4 Days Best Lhasa Tour
8 Days Tibet Everest Base Camp Tour
If you are interested in any of those places or Tibet tours, please feel free to contact with us.