I agree with everything that SWAFA30 said. Another advantage of getting a college degree is that it might actually help you in a flight attendant career. Everything else being equal, most airlines will pick a college graduate over a high school graduate anytime.
Having a college degree is (or at least should be) an indication that you know how to think for yourself and to reason through problems. Being a flight attendant is probably the most unsupervised non-management job in the world. You will spend your days at 30,000 feet in various places around the U.S. and possibly the world. Your immediate supervisor will be at a desk back at your home base. I have a friend who flys for ATA. He is currently on a 7-day trip to Shannon, Ireland- Kuwait-Bucharest, Romania-London, England. His supervisor is in Indianapolis, Ind. In an emergency or when a problem arises, he can't run to his supervisor for advice. He has to be able to handle the problem himself.
Do NOT waste your money on any school which promises to train you as a flight attendant. Every airline has it's own training program which is approved and overseen by the FAA. To work for that airline, you have to go through its training program which vary in length from 4-6 weeks depending on which airline it is. An airline, such as Southwest, which flies only 1 type of airplane usually has a somewhat shorter training period. AA which has 5 types of a/c just in its domestic fleet has a longer training period.
Make sure that you hone your French language skills as much as you can. I know that the test for language speakers at American Airlines is very difficult, and it is idiomatic, not just textbook stuff. They use a lot of what I guess you would call slang and everyday expressions to make sure that you can communicate with the average French speaking passenger. However, don't assume that being able to speak French will automatically get you an assignment in the International flying for an airline. International is considered a perk of the job at most airlines that fly outside the U.S., and jobs are awarded based on seniority.
Be aware that unless you want to fly for one of the domestic low-cost carriers, such as Southwest, Frontier, Airtran, or JetBlue, it is going to be awhile--several years, in fact--before there is any new hiring of flight attendants. Most of the major airlines, such as my airline (AA), have 1,000's of flight attendants on furlough right now. At AA, it is over 5300 flight attendants. Under our contract, AA can not hire any new flight attendants until all of us who are on furlough are offered a chance to return to work or our recall rights expire. The last group of us furloughed do not lose our recall rights until June 30, 2008. (Another use for that college degree. It will help you find a job during layoffs from the airline.
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All that being said, go for it. I'm 59 years old. I started flying just 4 years ago. I have a Liberal Arts undergraduate degree. I worked in the oil industry for many years as a computer systems analyst and consultant. I love being a flight attendant and can't wait to be recalled to work (for me, it will probably happen before the end of this year). And, I will tell you that you will know very quickly if you have picked the right career; so, you won't lose that much time if after doing it for awhile you decide that being a flight attendant is not what you want. And, that's where the usefulness of that college degree kicks in again.