I'm a union apprentice that received a 1099 MISC (Box 3) b/c of a grant giving us a few $/hr to attend class. Is it correct to file a schedule C? What is my "business"?

I am an apprentice for a trade union.  We receive a few $/hr as part of a grant when completing course hours/training at the apprenticeship school.  I received a 1099 MISC with income in Box 3.  Turbotax wants me to treat this as a business and file a Form 1040 Schedule C.  Is this correct?  What is my "business" and am I the taxpayer that operates it?