The audio stuff comes with the book. The only thing you'd be missing are the worksheets they give out, but tbh, you could do without them. Just practice the kanji and sentences using words from each chapter. The book's exercises should suffice. As far as speaking goes, I'm sure you could do well w/o too much direct speaking practice, since you'll be going into 1b which is still a beginner class. If you start studying now though, I'm sure you could drop by the instructors office hours... You'd have to ask them though.
Also, use other sources to supplement what the book is teaching you. You could use Youtube, for example, to help you with pronunciation.