Determining requirements for a teaching license ?

The information in your first sentence is incorrect. You need to do better research. Some states only require that you have a Bachelor's degree plus an intensive teacher preparation course, plus exams.

Do your research solely on the credentialing website for the state in which you want to teach, so that you don't get confused.

Go to the state Dept. of Ed. website for the state you want, find the page listing the requirements for teacher credentialing, and find the segment outlining the requirements to be credentialed in a specific area or at a specific level.

Again, every state is a little different. Choose one state and fulfill the requirements as outlined. Then get a job in that state.  Later, if you want to teach in another state, you can look up the requirements to be credentialed in that state as a teacher with an existing credential and experience.

You need a teaching degree in the specific area that you plan on seeking a job in like Math.  Most people will just seek a teaching bachelors or masters degree in an area like "Math".   You won't be able to get around the degree by just taking certification tests since you will be competing against 100 other people who have the favored degrees.  There's a difference between the minimum the states require and what is likely to actually get you a job offer.    For classes you need to talk to a student counselor at the specific University you plan on attending.