The tour bus left for the Qinghai lake from the Xining bus passenger transport center, not Xining bus station. If you are standing facing to Xining railway station entrance, the building is on your right hand side (picture attached). The trip took 3 hour to qinghaihu erlangjian scenic area, and the driver will give you 3 hour for sightseeing, which was enough. Then you will ride the same bus back to Xonjng. Driver was helpful and try to communicate with you via translator. Thank you.