From Songpan, I will visit Bipenggou. Could I have any advice, how I go to Bipenggou?

Hi, Henry! There is no direct bus to Bipenggou. You can take a bus at Chuanzhusi Tourist Bus Station to Wenchuan first. There are usually three buses a day leaving at 7:20, 8:00, and 14:00; the bus fare is around CNY70 and you will arrive Wenchuan in around 3h.
There are frequent bus from Wenchuan to Lixian and the duration is around 1h. You may pay CNY20 for it.
Upon arrival, charter a car to Bipenggou at a cost of CNY20 per person.