How do i get letters of recommendation from professors?

Professors don't need to remember to write a letter of recommendation. If you got a good grade in their course, particularly an A, then it's always worth a shot to ask them to write the letter. If you wait multiple decades to go to graduate school, then the least of your problems will be getting recommendation letters, since you'll probably have to take/retake a few core courses for the masters program just to prove that you're prepared. There's plenty of good masters programs in education in SoCal besides USC, and other schools that might be less stringent about the recommendation letters. Some of the CSU's now offer PhD. programs in Education.