I know I have done it in the past but now I can't figure out how to add sessions to an ongoing event before play happens. Can someone please help?
You don't need to add sessions to an ongoing game. You only do that if you have an event scheduled--and you don't even have to do that. The only thing that the number of sessions impacts is when you print your tracking sheets.
If you want to edit an ongoing event, just click on the title of the event and look in the upper right corner of the screen. You'll see a choice for 'Edit' and a choice for 'Sessions'. Choose Edit, make your changes and save. But ongoing events don't have # of sessions because they're ongoing--at least mine didn't. Personally I avoid building ongoing sessions since it's easy to overwrite you old work if you aren't really focused.
But like I said, when you go to report your event it doesn't make a difference if you built the event as 3 sessions or 30 sessions. You report what session you ran, and then you 'Save Changes and Report Another Session' until you have everything entered.
The system is complicated to learn but once you understand, it all makes sense. Thanks for going through the trouble to report your sessions! It only gets easier from here :)