Can't say. There are schools ready to take money for almost everything. Some good; some not so good. Good schools do not always produce jobs. I really think you should check with a couple of airlines before comitting the time and money. Also, try to find out if most airlines don't do their own training. If they pay you to train, you will be way ahead of the game, and probably have a job when you complete the training. If the airlines do have their own programs, and don't accept you, you might reconsider the whole thing.
Do you mean you would quit school for this? If so, depending on what type of school you are attending. If you were in the US and planning to quit high school, just for example, you would have removed yourself from consideration as a flight attendent. Period.