It depends what dancing you are doing at the class or what uniform the class has.
basshunter-dota
YES The younger you are when you start the better you are likely to get
It is not very hard at all. it is a little hard if you don't have patience but other wise it is not that hard. It also depends on what type of dance you are taking.
I buy my dance clothes off www.discountdance.com It's a great site to buy all your practice clothes, costumes and shoes.