According to AOPA, over 2,400 applications have been completed in IACRA for remote pilot certificates since Monday when Part 107 rules took effect.
Further to that 16,000 people have completed the FAA’s Part 107 small UAS online course.
If you are looking for Part 107 information AOPA has done a great job of laying it out here.
https://www.aopa.org/go-fly/aircraft-and-ownership/drones/guide-to-remote-pilot-certification