Hi,
i did nvq 1&2 at evening college over 18 months, i did have gcses and a levels, but i needed to just do a basic numercy/literacy test at college for entry and an interview, it was quite basic stuff. The interview is more important as you get to chat to the tutor and really show them you are passionate and going to be commited to doing the course and show them you are worth taking on.
I did have a years experience as a junior in a salon but that was 13 years ago, some of the things i learnt stuck and were relevant, other things had moved on a bit.
Whilst doing my levels 1 & 2 i volunteered a morning a week in a salon too, that is now a compulsory requiremt apparantly.
i would just plan well in advance, go and see the college's learning support advisors and they will explain all your options, it's really worth doing if its what you really enjoy doing. I haven't the opportuniy to work in a salon at the moment as i have a small child, so i have gone mobile straight away, which is good but very daunting at times and i think its only through age and life experience (am 36) that i can deal with some awkward clients or decide whether or not i am confident enough to do something or not.
if you're under 25 and not done an nvq before you get your fees paid for, which saves you about £600 plus you have to buy all your kit which can be quite pricey. Just things to take into consideration.
All the best anyway, hope you find the course you're looking for!!