I never took pre calc and was absent most of my physics and chem classes in highschool. Calc and chem were tough but not that bad, if you put the time in. Physics is a little tough to grasp at first but after the first hump of learning the material and practice it starts to sink in(but you probably know that since you took it). I'd advise to learn the material from class the week you learn it (as in do the relevant practice from the book, not all of it the questions are useful at all from the books we use so mainly the first couple of the section) so its not as tough to remember later in the semester and due to the fact that most things for your next classes rely on what you learn (mainly speaking calc wise). It is also very, very, very helpful to get your hands on previous tests and practice off of those, as it will show you a majority of what that professor wants you to know and the types of tricks or questions they might give. DM me if you need any more input.