Hello, I have just finished 2 semesters of University Biology.
I'd recommend starting you're study with Genetics/DNA, you can almost guarantee that will form a large part of you're lectures and labs. This will include studying the structure of DNA, Transcription & Translation, Mitosis & Meiosis and Genetic Technology. Also cellular biomolecules such as your Carbohdrates, Amino Acids, Lipids and the structure and function of Cells (eukaryotic and prokaryotic)
Some other topics I would focus on that are likely to be covered; Nervous System, Homeostasis, Metabolism, Hormones & Reproduction, Animal Development, Basic Immunology and Viruses, Microbiology (Bacteria structure and Function), structure and function of the lungs, heart, kidney, brain. These were the main topics that were covered in my last semester of Biology.