due to reasons out of my control I had to have a gap year when I left school so I did the Princes Trust 12 week self-development course and for the rest of the year I volunteered full time in a charity shop. That doesn't sound very exciting but it was life-changing for me, it gave me alot of confidence and gave me the motivation to want to succeed in life, in contrast to the attitude I had at school where I didn't care and never worked hard.
When I was at college, I worked extremely hard and also volunteered with the police and learn to drive and then when I came to uni, I continued volunteering in various other places. Last summer I lived and worked in America all summer at Disneyworld and this summer I'm doing a Tallships Youth Trust voyage/Race in Norway.
The point I'm trying to make is, these things don't just come out of thin air, you have to build up to them gradually and as each experience passes you by, you will grow more stronger and be more able to deal with the next experience that comes along plus it opens doors for you that previously weren't there. In the short term, set yourself small targets to work towards and commit yourself to achieving them and then think of the bigger picture and what you want to do in the long-term. You may find that your ambitions change as you go along and lear more. The only person in the driving seat is you, you can have all the ideas in the world but you need to be the one to act upon them.
Your age doesn't matter, not alot of people have done many things at your age and when you consider that some people in their 70s graduate with degrees and skydive e.t.c. you really do have all the time in the world.