Your progress depends more on your level of motivation than anything else. Whether you stay aloft for 30 minutes or six hours depends on the amount of lift on that day. It mostly depends on the atmospheric conditions. You may not realize it by just looking up at the sky, but no two days are ever the same. Lessons are offered to people of any age, including young teenagers.
Kids mature very quickly when they take on the responsibility of being a pilot.
All of a sudden, whatever they say or do in or near an aircraft has great importance - both to themselves and to others around them. They quickly realize their worth and their self-esteem increases tremendously. If they have a distorted view of themselves, or of others, or of life in general, everything comes into perspective during training. Only qualified people are allowed to fly, but, barring serious physical or mental handicaps, any one who wants to, can become qualified. Solo flights are allowed at age 14, with 16 being the minimum age for obtaining the private glider license.