This is an old topic, I know, but I'll reply in case others have the same question.
If you are just looking to learn Calculus, you can choose either one. In fact, MA005 would be a good third choice.
Otherwise, MA101 was conceived as a first-year undergraduate college course, and Math013 is like an AP (Advanced Placement) high school Calculus course.
Kind of a long story, but the reason we have Math013 has to do with our catalog and plans from several years ago. We have kept the course, but Math013, MA101 and MA005 cover much of the same territory -- introductory Calculus.
Incidentally, if a student is looking for college credit, then MA005 is the way to go...