> Unfortunately, I don't have four years to get a teaching degree, let alone a master's degree, let alone $50,000 to pay for one.

Depending on what your undergrad is (preferably STEM), there are plenty of districts that will hire you, let you teach on a provisional license with a crash course, and pay for you to get your teaching qualification.

See this article for some examples:

https://edsource.org/2022/what-you-need-to-know-to-become-a-...

In CA, the term of art to look for is “intern” or “internship”.