Tracking what webinars/events contacts are attending in CRM

I’m building out my nonprofit’s CRM in Part of this CRM is a contacts board.

How do I track who is registering for our webinars, events etc in this Contacts board? For example, lets say 100 people registered for our webinar. I have all of their emails in a spreadsheet. Is there a way to automate finding these people and marking their attendance? How should I mark that? tags doesnt feel right. An update or something?

Grateful for any advice.