Yes, as an organiser you can restrict attendees entry for a particular session by using the "Control who can join" session.

Kindly refer to the help article - Control who can access your event session (restrict session-based entry)

Restrict other attendees from the session. Only a host and co-host have these rights. 

If they find someone spamming/abusing, they can report the person and then the host can block them.

Need more help? Contact or visit our 24*7 Support Lounge.