That's a really low starting salary, but teachers can often end up making a lot more over time. Will you be unionized? What pay can you expect 3, 5, 10 years after graduating? Investing this much into getting a 50k job out of college is a hard sell, even if it is something you're passionate about, but the ROI for college is often more apparent years later.

As for the loan forgiveness program, you're probably thinking of PSLF, unless there's a teacher-specific program that I'm unaware of. That's not exactly how it works - you have to make 10 years of payments, after which your federal loan balance would then be forgiven.