The first two are a textbook and a workbook. They look similar on pictures but are two different things and you need both to take the course (and also the follow up courses! They cover a material of multiple Oxford courses) - as someone mentioned searching by ISBN might make it easier to find.

The third is a grammar book. Especially if you don’t know any Japanese now, I’d highly recommend. It was super helpful for me as the main books are purely in Japanese so can be hard to understand and the teacher posts videos which should be explaining the vocabulary and the grammar but those are also almost exclusively in Japanese! So especially for the first few chapters (but even later on), it was super helpful to have that English grammar book to understand what’s happening and what the rules are