A year of college study is sufficient enough for many 4 year institutions. What they really want to see if that you can satisfactorily handle college-level work. A year or more demonstrates this.

The department offices of most community colleges have requirements for some local 4 year schools. This helps match-up which classes are transferrable to this school or another. You can also contact the department at the 4 year school where you’ll be transferring to see what they’ll take from the community college. Some classes transfer, others do not. And some schools require certain classes be taken at their school. So you may have to repeat some classes if that’s the case.