Lol Timothy. I am fourteen, honest! I may seem older by the way I type - my dad types just like this and has done for years, and it's rubbed off on me in a way, I struggle to NOT use correct spellings and grammar, etc. The avatar is me, just as it is on my portfolio (www.liamhammett.co.cc (well, my slightly old portfolio)).
Look around locally for what can be done. For example I bumped into a church person not too long ago, we got discussing about the church website and the next thing I know I was upgrading, moving and designing their website. The church is very big with alot of members so this one project got my name around and brought on another one. Also check out shops around your area, my family use a Frame Shop located nearby, I went in one day, got talking about their website and the next thing I know I'm designing a brand new website for them and my business cards are on display in the shop. Also REMEMBER above all things : Make sure you can do the job BEFORE you take the money.
But it's kinda hard to walk up to someone and get chatting about doing a website for someone at my age. That and I'm nervous.
You need to delare yourself as self employed and pay tax if you earn of £15k a year You can't have nerves about talking to people because you'll miss the best opportunities, if you want to be successful as a freelancer then you have to put yourself around and let people know what you offer. I've only just realised your male.. thought you had long hair in that pic whoops lol