You had Dr. Moro as instructor for this. She's one of the best around. Also, she wrote the study guide that goes with your text. Use those!
If you are specifically concerned about phonetics, one of the best websites around is:
https://webdisk.ucalgary.ca/~swinter..._html/ling341/
The course 341 at Calgary is a full semester of nothing but phonetics. His slides are good, if you want some more in-depth knowledge. Obviously, only a part is going to be pertinent. So be selective.
First year courses are usually tough, because they try to cover a whole field. If you intend to continue in Linguistics, you should aim a bit higher than 70s. A is 80+, and that's how you get 10, 11, or 12.