Pop along to your nearest club as soon as you can. Both Cambridge and Dunstable are good clubs. Both will have young people. Have a Trial Lesson. Ask about the money. If you can afford it, do it. And spend as much time as you can doing full time courses to get the inital drudge out of the way. Once you have reached a reasonable level, say after a year, you will know what you want to go for. Competitions, Aerobatics, Cross-country, Wave Soaring, the Vintage glider scene etc. Each has their own set of attractions. It just depends how you are cut. Only time (and wanting to see my family) prevents me from gliding now, otherwise I would be off gliding every weekend.
PM