This course assumes that you have taken everything in the standard high-school precalculus sequence, e.g. you are fluent with algebra, know some plane geometry, trigometry, logarithms, and similar. Calculus is not required, but may be helpful because it gives you more experience manipulating mathematics.
Some parts of this course discuss computer algorithms in the abstract (pseudo-code). If you have very little or no programming experience, we strongly urge you to take CS 125 first. However, it is not critical to know the full content of CS 125, nor does it matter what programming language(s) you happen to have used.
If you aren't sure whether you have the right background, come speak to one of the instructors.