Where can I get the nuvaring?

So I'm 15 (yes underage I know) and I want to use the 'ring' because I just really hate condoms, I've read up about how to use it etc and possible side effects but one thing I couldn't find was, where can I get it from and how much it'll cost? Like do I need to go to my GP, or just like buy over the counter from a pharmacy, or from somewhere like boots or from a sexual health clinic? And if you do have to buy it is there anywhere that offers it free? Thanks x