Well this isn't exactly the right place to ask your question.. but I'll answer it anyways. You should know how to take basic derivatives (Quotient Rule, Chain Rule, Product Rule etc) and integrals (U-Substitution, Trigonometric substitution etc) of a given function, and separation of variable integration. If you can do that well, you shouldn't encounter too big of a trouble during the class. (Don't worry about shell integration, power series, those kind of stuff. You don't see that in Diff EQ 1)