Where can I find my existing licenses and their expiration dates?

Logging in to your JetBrains Account will allow you to see all the licenses you own and their expiry dates. If you do not have an account, you can create one and connect your licenses to it. 

An Organization/Team Administrator can view a breakdown of the licensing they can manage from the Organization Profile page. Here you can export all of the licensing onto a spreadsheet, or click the links below each Product to view the individual licenses and their expiration dates, assignees, etc.

A Personal license customer or Commercial license User can view their licensing and expiration dates from the login page at https://account.jetbrains.com.