I'll just give some general tips. I didn't do too much during the holidays but the key thing is to maintain your level in French as best as possible. If there are some summer classes near you, even if its just a few days, maybe consider that
For what its worth, I didn't use Schaum at all (did 2 pages), I found it boring and honestly found duolingo as useful to practice getting the little things right (which is an important thing in French)...I probably credit my year 10 teacher with that though, he drummed all the important grammar points into us. So it's not the end of the world if you don't use the whole book.
I'd say one of the most important things is to get good with listening techniques and practice them throughout the year (as your listening SAC is one of the first ones then there's nothing after that). Read the questions carefully and pick out the key words during reading time, listen for them, etc. etc.
Writing is also very important. Try to do one practice piece a week, 200-300 words. It'll help you write quickly and expand your vocab. Getting a rough plan of what you want to write first is helpful, and also pay attention to the conventions of each text type - eg: title, author name, register, address, date, etc.
Speaking throughout the year will help so much. During year 11, I developed the ability to hold a basic, short conversation, but through speaking most of the time in french in year 12, I got to the stage where I was comfortable enough and able to hold a conversation. Afaik, a lot of teachers make students speak only in french during class - at first it seems a bit unreasonable and tricky, but you'll be thankful for it eventually!