How Often Do New Projects Become Available?

I just signed up earlier through a link I received though my school email for a position that was related to my field (Criminology) but after getting to the Handshake AI dashboard, there aren't any projects related to Criminology. Is it normal for the field you signed up under to not appear as an available project? And my second question is the title, how often do new projects show up? Most of the ones I can currently see are asking for people with Phds in unrelated fields to my experience.