Hi there, Rodel! Welcome back. 🙂
Unfortunately, there is no easy way to require fields in the admin editing screen for events. It may very well be possible with some custom development, but unfortunately, that’s outside the level of support we can provide here in the forums. However, we do offer our full documentation to help guide you if that’s something you’re looking to take on.
Also, you can suggest that feature to us on our UserVoice page if it’s something you’d like to see in a future release. We check there often for popular ideas.
Sorry I don’t have a concrete solution for you here, but let me know if you have any follow-up questions and I’d be happy to help.
Cheers!
Geoff