I want to travel to Xian (Terracota Army) to Sichuan where the Giant Buddha is. what is the bus route to take?

The Buddha is in Leshan, but there is no direct buses between the two places. It is suggested to take trains to reach Chengdu. Upon reaching Chengdu, you can go to the Xinnanmen Bus Station where you can find frequent buses to reach Leshan Buddha directly.

Thank you very much for your reply- so, its in Leshan... do you have any recommendations for accommodation in Xian?

But what is your budget? Anyway, if you want a budget one, the chain inns or hostels, such as Jinjiang Inn, Home Inn and Hanting Express Hotel, are good choices. If you want to stay in the city center, Bell Tower Hotel, which may be a little expensive, should be considered.