There's an On Demand PC Studio Fundamentals course available on Bentley Learn:
Filter by AECOsim > PC Studio and you should be able to navigate here:
Also, Bentley user Doug Fitzpatrick wrote up a nice document:
And there's always YouTube... https://www.youtube.com/watch?v=_Zs3wn-gjh8, https://www.youtube.com/watch?v=qNdbTU8G4G8, www.youtube.com/watch , etc.
oldie but goldie from GA Tech
/cfs-file/__key/communityserver-discussions-components-files/5917/Tutorial_5F00_Custom_5F00_Object_5F00_Bentley.pptx
converted to pdf/cfs-file/__key/communityserver-discussions-components-files/5917/Tutorial_5F00_Custom_5F00_Object_5F00_Bentley.pdf