You definitely want to go over contracts, common law requirements for a contract vs the UCC and when each applies (UCC applies only to sale of goods), know what's needed for a modification to a contract, what's needed for acceptance of a contract to occur under each, know that revocations are generally effective when received, and acceptances are effective when dispatched (the mailbox rule). You'll probably see one or two questions on the parol evidence rule, which basically disallows any verbal statements made prior to or contemporaneously with the contract signing from being used at future hearings, but does not effect future verbal arguments subsequent to the contract being signed from being administered. Know the security regulations (especially criteria necessary under the 1933 act vs the 1934 act to recover due to fraud/misrepresentation), and know the basics of bankruptcy, which chapters of bankruptcy are available, criteria to be involuntarily petitioned into bankruptcy…
Understand sureties, what happened if one is released as a surety and what effect that has, etc. Understand requirements to attach and perfect, and have an idea of the order of preference for secured transactions.
I always found agency to be pretty straightforward, but basically know who's liable for contracts entered into with a disclosed principal, and then an undisclosed one. Otherwise, there's plenty of nuances to blaw, but if you know these key elements for each section I highlighted, you'll have 90% of blaw covered.
And yes, you need to study blaw before taking the exam! You don't have enough cushion to go into the exam without studying blaw a bit.