How to make an Event registration form where you can choose which event you are registering for?
You can create a Price Set (used for Event) with a Price Field for each Webinar (Input Field checkbox). You can set a Participate Count and Max Participants for each Price Field. When you create your event, under the Fees Tab, Enter the Price Set name. You can charge a different amount for each webinar or $0 for all of them.  I know this does not create 3 separate events in your reports, but it does give you the ability to automatically close registration when full. You can filter your reports by Price set boxes.