Starting ballet again?

I used to do ballet. I started when I was 4, and when I quit I was grade 2 and 8 years old. I started ice skating when I was ten, and now I'm twelve, I'm a level gold plus at ice skating (you have levels one to ten, then bronze, silver, gold and gold plus), but I want to quit. 

I was wondering if I could start ballet classes again, I just don't know what classes to take or what level to start at, it's been four years and I can't remember any moves except first, second, third position ect...

Also, I don't know if there are classes for people my age, and were I would get them. I have a friend who might know a place but she does tap and modern not ballet (I live in England.)

So basically, what level should I start at and are there any places anyone knows of that are around Oxford?

P.s I don't plan on going pro, I just want to do it as a hobby. Also, after I quit ice skating, I want to still be doing a sport. 

Go for it. Just research dance studios in your area. Observe a class if you can. Let the instructor evaluate you and he/she can suggest which of their classes is most appropriate for you.