Hi lhilairerf14,
Welcome to the HVAC Group!
In the very front of the book it will tell you how to gain access to MyHVACLab. There you can have access to many necessary videos and your tests. Start on unit 1 and read everything carefully. If there is anything that you do not understand, re-read that particular part. If you still do not understand it completely, then ask me, your instructor and I will be happy to assist you.
At the end of each unit you will find review questions. Study the review questions to see how well you learned the unit. If you have difficulty in accessing the MYHVACLab, you might need a password, the office and/or student help desk can help you with that.
Good luck with your studies!