You might think that you need a leotard, tights and ballet shoes, but that isn’t true. You can wear whatever you’re most comfortable exercising in.
As far as shoes, you can just pull on a pair of slip-resistant socks that usually worn for yoga or Pilates, rather than ballet shoes. The sticky pads on the soles will stop you from slipping on the floor or mat. But them but if you really want, you can purchase canvas dance shoes which are cheaper than the satin slippers that ballerinas are known for wearing.
Many of the Ballet Beautiful stretches and exercises are done on a mat like one you use for yoga so if you already have one, or even an exercise mat, you have no need to purchase one.