VET102 doesn't have textbooks. The webinar may be going over material from either of the three study units of Intro to Vet Tech. I remember when I first enrolled in 2012 I attended my first webinar. I was on Behavior and the webinar topic was about restraining animals.
The webinars are a continuous cycle and are picked up from the last slide of the previous week's class. So, a student that has been enrolled for several weeks may be attending the webinar that is discussing the part of the study guide that they are at, while newbies (like yourself) are attending the same webinar but it's discussing a different lesson.
What you can do is watch the recorded lectures on your My Courses page that will match the lesson you are at -or- continue attending the Intro to VT webinars and follow along in the study guides even though you haven't read them yet -or- wait until the webinar "circle of life" starts over again.
You'll start using your e-books at the start of Intro to Biology. Perhaps at that time you'll have access to CourseSmart. Anatomy & Physiology and Math Applications also have e-books.