Q. How to apply attributes to a product?
A. Make product variable, not simple, also check box “use attributes for variations”. Then you will be able to choose from available attributes.
Q. How to notify customer that the order was shipped?
A. Go to Orders. Click on the order you just shipped. Change status to “Completed”, in “Customer Note” field provide the tracking number and click “Save Order”, email will go automatically to the customer, notifying that order was completed.