Yes sir you need to enroll those subjects in a college. Basic ROTC is two semesters, you enroll MS-1 for the 1st sem, and MS-2 for the 2nd sem. Advance ROTC is four semesters, so you enrol MS-31, 32, 41, and 42 respectively. After finishing 6 semesters of ROTC, you then take MS-43 (Probationary Officer Training Course) which is 3 months. After which, you are commissioned as a 2LT in the reserve force.
If you are not qualified under Circular 30 to be commissioned and you receive your enlisted AFPSN through other means outside ROTC (UADT, BCMT, Technical Br, etc) you need to go through ROTC to be a commissioned officer in the reserve force.
If you want to be in the active service and you are not an ROTC graduate, you can join the OCS (Army), PAFROPP (Air Force), or NOCC (Navy). The course duration is 18 months, after which you are commissioned as a 2LT in the regular force.