To find the most updated list of base content, please go to www.iracing.com/membership and scroll to the bottom. You will see images of all cars and tracks that come included with your initial iRacing Membership.
For a more organized list, you can go to each link below:
https://www.iracing.com/tracks/
Click the filter to list only "Included with Membership" content 
We provide all of the cars and tracks needed to run the Rookie races.
Any additional content will need to be licensed to your account.
If you have any additional questions, please email us at support@iracing.com.