I’m a new National Guardsman, and I haven’t been paid for my first two drills. My recruiter hasn’t resolved it. Who should I go to next?

Call an Army recruiter and apply for active duty. Problem solved. This stuff is easy.

Your unit, not the recruiter, is responsible for paying you.
What is needed in order to do that is a DA 1380 signed and certified by a person with personal knowledge of you completing the work detailed on the form.
My guess is that either your recruiter has not completed the form, did not transmit it to your Unit Administrator (or pay official), or the UA is not putting it in for pay. Those are really the only three possibilities, so follow each in order until you find resolution.

Usually you should have a Readiness NCO. They are the ones that log that you were there for drill. But in an RSP they may not have one. I would just keep bugging him just about everyday until you get a date to which you will get paid. I have seen soldiers in the Guard be on active duty for training and not get paid for months. The National Guard stopped paying while I was in Ranger School. All I can really say is that I hope you enjoy what you will be doing. If not you aren't going to like. You are seeing how the Guard works most of the time when it comes to pay issues. I went the route of MSG Dan Castaneda. I left the Guard and went back to the Regular Army.