Hi,
with help of sap help links based on cubes or help of BI content you can find the standard queries.
Later you can install them from BI content.
Once query is in active version, later you can open same query from analyzer or designer.
Assuming as required data flow was built on your server.
to know standard queries you can check table - RSRREPDIR .
for purchasing rand sales, you use their standard name like 0PUR* and 0SD*.
Thanks