How to use Rules to populate reference product after creating a Commerce product? After a Commerce product is created I need to create a new product display node and reference the product in a field. 

This is my first time using Rules. I can create a new product display node but I cant figure out how to populate the 'referenced product' field.
Despite the limited information in your question, you should be able to create such rule (using the Rules module) like so:


Use a Rules Event that is related to "When Commerce product is created" (something similar to "After saving content"?).
Add a Rules Condition to make your referenced product field become available to use in a Rules Action. This condition can be either of those alternatives:


"Entity has field".
"Content is of type".

Add Rules Action "Set a data value" for your referenced product field.