About to take a 6 week vector calculus course after not dealing with calculus or vectors for a while, what stuff should I brush up on?

I haven't really done any calculus in a year and I haven't touched vectors since linear algebra in the fall(did really well with both tho). People are saying this is one of the hardest math classes and I'd imagine with only 6 weeks they hit the ground running so I really don't want to be rusty going into this. What are some important concepts to understand, facts to memorize, operations to practice...