Is it best for me to switch to Active duty from National Guard in order to be able to go to drill sergeant school?

Well the Army Reserves have Drill Sergeants. The 98th and 95th div which falls under the 108th. But you are correct only NCO's are Drill Sergeants. It is a hard choice you have to make if you want to work your way up the enlisted ladder to become a Drill Sergeant then submit an officer packet. But if you are in ROTC and have already contracted I don't think that would be possible or you will owe the government for your tuition. I would speak with your ROTC cadre and see what options you have.

Well, you have a few years before you can submit a packet for Drill Sergeant. Whether you stay Guard or go Active Duty, you will have to make a choice as to which one you want to do first...Drill Sergeant or Officer. One thing you can do is to go to college, get your degree, then once you make Sergeant, submit for DS. Once you are done with DS duties, submit a packet for OCS.

You can be a drill in both Active and Guard. You have a long ways to go before you are eligeable. Along the way you can earn a college degree while serving. If you earn enough college you can decide after DS duty whether or not you still wish to become an officer. Good luck!