Hiya,
The only advice I can give you is to search on the internet using google, ask jeeves etc and put in 'Late beginners' or go to
www.itda.co.uk or
www.dtol.ndirect.co.uk (dance teachers online).
Search for schools and teachers in your area, and start ringing around, because, even if that school can't help you they might be able to put you onto someone who will.
I'm a late beginner and I didn't think there would be anyone catering in ballet and tap for beginners of my age but I'm going to be starting private ballet lessons and adult tap lessons along with classes. I was surprised at how many schools did lessons for beginners of my age.
I'm determined to become a professional dancer because I know it's in my heart and I know it's something I can do. If it's what you love to do then you will get there.
Don't listen to what people say about it being to late to learn because it's simply not true.
Your family and friends, I'm sure, will support you in anything that you want to do.
All you have to do is believe in yourself and people will believe in you. The only thing to remeber is, Don't give up.
Hope it helps