I would not take out a loan. If you are a full time high school teacher, you must have a steady job and be making somewhat decent money. I would finish getting your private this winter/spring with money out of your own pocket. Then I would do some cross country flying to build up time. You will need this PIC cross country for both your instrument and your commercial licenses. However, getting this time will be cheaper (because there is no instructor involved) and it will be more fun (you should take all your friends for rides). Only pay with the money that you have.

Work a second job this summer. SAVE, SAVE, SAVE this coming summer and next school year. Then use whatever money you have to get your instrument, commercial, and CFI ratings after next school year. If at this point you don't have enough money saved up, then take out a small loan (5-10k).

Trust me. The last thing you want is to be a flight instructor or regional FO barely making 20k a year and needing to pay off a huge loan. Most of these guys are struggling to get by with NO LOANS. The other terrible part about loans is the interest adds up real fast. Your 30k loan could cost you 50k in just 5-6 years. BIG DIFFERENCE!

You should do everything in your power not to take out a loan.