^^ and is it worth it (junior year, that is)?
The “C” portion (i.e. new topics in Calculus BC) build off of a lot of AB topics, so for the most part, I wouldn’t suggest studying them until you have a firm grasp of derivatives and integrals.
However BC covers a lot on sequences and series, as well as testing for convergence/divergence, and many of the tests don’t require a huge calculus background to be able to understand them.