I'm sure once you start pointe classe your teacher will give you lots of exercises. You'll find that even if you're eager to spenf lots of time en pointe, at first, your feet will get really sore from the different pressure and from the shoe rubbing against parts of your foot that haven't had to deal with that before!
Make sure that when you get your shoes you tell the vendor that these are your first toe shoes, and say how much ballet you've had (they'll probably ask you all sorts of those questions). Try on all the shoes they recommend. Fit is VERY important. Go with the one that is best for your foot, and trust the vendor as to how it should fit (it will feel too small when you're on a flat foot - sliding down your heel - but your feet will feel very long).
Ankle strength and alignment is crucial. Do releve and pique exercises to make sure your ankles aren't wobbly, and are straight. Once you go on your toes, you'll have a lot farther to go, and you won't be able to grab the floor with your toes to help you balance, so your ankle will take all the strain of holding you balanced straight over your foot.
If, once you start pointe lessons, it doesn't seem like you have enough exercises to strengthen your feet & ankles and get used to the shoes, ask here again.
Good luck!
