Head Start on APs

Next year, I will be taking 5 APs at high school:
Calc BC
Chem
Lang
Physics C
US History

and also self studying macro/micro economics.
I would like to get a head start on the APs during the remainder of this school year and over the summer when I have free time. I have some review books for some of them, can I start reading or learn some needed fundamentals for these courses so that the work will be lighter during the school year?

Can you? Why wouldn’t you be able to? Of course you can.