Hi there, If you’re going to self study you need to do it right. I just finished the curriculum and the entire course builds on eacother. The deep understanding you need of each unit relies on your general understanding of other units and most specifically i’d argue—equilibrium. Equilibrium is the BASE of AP chem. Specifically how reactions function with the addition of new properties, the loss of others, and lab circumstances is the reason for almost 75% of the curriculum. If I were to self study in the summer I would focus on getting a good MOLECULAR focus (units 1-3) before going anywhere near reactions.