So you want to teach high school math? Great, sit down for a minute and lets talk.
How well did you do in college majoring in Mathematics? What? You didn't major in Math? You majored in Theatrical Production? What in the name of Zeus' Beard are you doing here?
Oh, I see, because of the lack of Math majors and the increasing demand for Math teachers, the State of California will credential an applicant to teach high school Math with either a Mathematics degree or the passing of 3 tests.
So, you passed 3 tests and now you are a credentialed Math teacher? What??? You didn't pass all three tests? You passed only 2 and still you can teach? Ah, I see, passing only 2 allows you to teach up to Algebra 2, but not Pre-Calculus and above.
Wait, what does the 3rd test cover? Calculus? You can't do Calculus? You didn't take Calculus in either high school or college but you can teach Math on the high school level?
My problem with your situation is addressed almost every day in every classroom. First, how do you possibly answer "how will I ever use this" if you have never used this? Second, I don't believe in just giving students formulas. The volume of a right cylinder is V= π(r squared)h. The curious student, and I was, and I see them every year, ask, "where does that formula come from?" Door open. I ALWAYS take the time to then derive the formula for the students. For the above, I would first show that the volume can be found using a technique called "slicing" and second, I would derive the volume using the Disk Method of Volumes of Rotation in Calculus. Most, including the kid that asked, will be lost quickly, but to some, the few, the proud, the future,....it will open a door to great possibilities. They will stay after class and ask to see the derivation of other formulas. Then i have them. I show how to find volume a 3rd way. By integrating Surface Area. Rocking and shocking and wonderful mathematics that all begin to come together in "the Calculus".
Go back to school. Take a Calculus class. No, take 5. Differential Calculus, Integral Calculus, Vector (also called Multivariable) Calculus, and Differential Equations. Then take a History of Mathematics class.
Then come see me.