Recommending new/unrated events/movies?

I work on an events platform (

Users can rate events after attending them. I would like to build a recommendation system for new (as yet unrated) events.

At first I thought this was a collaborative filtering task, but since new events don’t yet have any ratings, I don’t think this is the right approach.

What’s a good way of recommending new (unrated) events to users? (or if we were talking about movies, how would I recommend as-yet unreleased movies to users?)