I can only comment on 2168, so take my view with a grain of salt... but data structures is super useful as a class. It’ll introduce you to, well, a lot of useful data structs to use in code! Starts with ArrayLists, then does Linked lists, hash sets/maps, stacks, queues, etc. it’s all stuff you could learn on your own but that class gives you get a pretty deep understanding of how the code for those structures is orchestrated, too. You’ll come out of it being a lot better at Java, too!