It really depends on how far you got into functions.

College Algebra is rules that you have to follow, so it should be very straight forward. Trigonometry I think is a little bit more challenging since you are starting to deal with functions (graphing sin, cos, tan, and using them to model real life situations... hopefully this was covered).

Calculus takes the basic functions that you should have learned in both algebra and trig and analysis them based on time .. Calculus is basically modeling things based on the rate of change [my calculus was into second year university so someone please correct me on this if i'm off].

if you are good at following rules to solve an equation then pre-calculus shouldn't be that hard. Mind you it will take a lot of hard work. What you should do is go pick up a pre-calculus book (hopefully the one your course will be using) and look through it. See if you can teach yourself the first chapter then flip to the middle and see if you understand some of it.

if you have the course outline that would help in letting you know what you might be up against.