Configure > Form Layout > Ratings

Meeting Request rating fields have a few purposes.

The Interest Level field - which is set as default to high, medium, low.   This field, if used in the form, sets an interest level - and this setting also drives where an attendee request will get ranked initially.  If they set it to high, it will get put above all the 'medium' and 'low' level requests they have already made - but below existing 'high' ones.

Also - the Interest Level field has a role in automation.  if you change the values and make one of them negative e.g "Really Low" - then this request will not get scheduled in the automation.  It will get skipped.   This is true whether its the Source Interest Level or the Target Interest Level.

Other Misc fields are for general use and have no immediate functionality. They can be set to any kind of topic - and they can be used on the Meeting Times page to create "buckets" for the requests to make manual scheduling easier.  OR they can be used in automation as a basis for sub-filtering to limit the requests that the automation runs on.

The Preferred Time field is more commonly used in unmoderated events where they are guiding the time used by the counter party to accept the request into a meeting.  This field is less useful in moderated events.   IF you wish to make the Preferred Time field required - set the Time field to be required.  Always leave the Date field as Read-Only.