I am looking to query Google Analytics to get # of Session broken down by Age for a particular url. Can someone help me to understand how to generate these results?
You will go to Audience > Demographics > Age. You will have needed to set this up prior to viewing the data, but if you have, this will show you all the data you need to view sessions by age. You can also use secondary dimensions to add age as a group in other reports all throughout google analytics.