Hi, welcome to ATARNotes!
I personally took notes by hand (dot-point form) based on whatever content from the textbook or presentations I found covered the study design dot points. My notes were quite sequential, first starting off with plasma membranes, followed by nucleic acids and proteins, etc. I also liked to highlight key words and phrases, because you are expected in incorporate these into your exam answers, and I found that pretty helpful too.
I like taking notes by hand over typing because in the end of year exams, you will need to write a lot, so I felt it was super important to keep my writing speed up to scratch. I didn't do mind maps, but I think they are a very good idea, because all the concepts in VCE biology do link really nicely with each other. So I think your idea of drawing mind maps digitally is definitely something you could try doing as well.