One skill you probably have already is plugging numbers into formulas, getting numerical answers with the help of a pocket calculator. However, this skill will not be sufficient to pass physics courses! Why not? What else is needed?
You must be reasonably adept at algebraic manipulations, able to solve algebraic equations for an unknown. A "formula" is an equation which tells you how to get a numerical answer. The "formula" for the acceleration of an object sliding down a plane inclined at angle q, with coefficient of friction m, is
a = g (sin q - μ cos q)
It would not be very useful to memorize this formula. Instead, you are supposed to learn the method by which this formula is "derived." That means, you memorize only a few fundamental "laws" (F=ma) and important equations from which the derivation proceeds. You will encounter problems on homeworks and exams for which you will have never seen the "formula" before, and will never use it again. You will have to use physical reasoning to get started, and algebra to finish.
You are also supposed to know the meaning of mathematical terms and the formulas for various simple geometric and algebraic quantities, in particular:
The Greek Alphabet
quadratic formula
Pythagorean theorem
trigonometric identities
exponentiation rules; logarithms (base 10 and e)
perimeter of circle, ...
areas of circle, triangle, ...
surface area of a sphere, cylinder, ...
volume of sphere, cylinder, ...
simple calculus (derivatives and integrals)
In addition, you need a vocabulary of normal technical terms. For example, you must know terms like horizontal and vertical. If a word confuses you, it is always a good idea to look it up. Don't wait for us to tell you! It's your responsibility to identify things that confuse you and get beyond your confusion. We are eager to help, but you have to ask!!
Appendix A of Essential University Physics has a list of mathematical relationships. All of the stuff in appendix A should be memorized. Students wishing to brush up on the needed mathematics can find help in various ways: You can talk to your TA, recitation instructor or course instructor. You can find introductory books in the library, or at the bookstore. There is even help on the web (try google and look for “basic math” or “basic calculus”).