Dear mysteriousmartel,
a lot of people in LEAP worry about their background ( I did too). If you can generally do well on the calculus course then you should be fine. It gives you a flavor of the type of classes you will be taking. Some LEAP students take only 3 classes a semester(preferring to concentrate on a few courses). You will find that you won't be any more disadvantage from the undergrads. Just be aware of the pre-reqs. Some you will need, some you won't. Don't take differential equation unless you have Calc 2. What specialization are you looking at?