Hi,
Don't believe everything you hear. It use to be that if you were older than 12 - 14 you were washed up as swimmer. Take a look at the age of the swimmersi in the past Olympics.
Age does have something to do with it, however that is only when you start to get into you sixties and seventies. if you are 16 or a bit older there is no problem starting to learn how to play the piano.
All you need to do is find yourself a good teacher(i.e. one that you like and likes you and also will listen to what you have to say and not think that he/she is a know-it-all). Practicing is a matter of preferance. practicing two hours per day (if you have the time) with a break in the middle is fine. On the other hand, if you cannot do it consistencly everyday and start skipping, it is better to practice 30 to 40 minutes every day versus playing 2 or 3 hours and then practicing two day later again. All that you gain in the 2 to 3 hours session will be totally lost. So the bottom line with paractice is be consistent and set aside a time that you will practice, faithfully, everyday.