You are not alone! High school science is a big step up for our kids. My daughter and I tag team read Apologia Biology when she did it last year. We do the same thing this year with Apologia Chemistry. We do the On Your Own exercises orally and I let her take the tests open book for the most part. I did have her do a few Biology modules in the more traditional manner just so she would be familiar with the process. I also have her narrate orally after every reading.
A friend of mind is in college and she says all of her tests have been open book. She just received her AA and hasn’t taken one test where she wasn’t able to use her notes and textbook.