Get your own information on pointe shoe sizing, to avoid dancing in pain. If you get exactly the right fit, the most pain you should ever feel is a spot where your tights were not smoothed out, or where your protective padding slipped. Foot injuries are avoided by a good fit, good training, good floors, and being strong enough in the first place.
Dancing in pointe shoes should not be painful - uncomfortable sometimes, yes. Getting exactly the right fit is a challenge - knowing how, and finding a ballet store that has a lot of different kinds of shoes to try on.
Some ballet stores have excellent shoe fitters and some do not.
Some students have one foot that is longer, or wider, or weaker than the other foot.
Pointe shoes must be bought for the longer foot, and the shorter foot can be padded differently. Just like you do with your street shoes.
A weaker foot must be exercised twice as much as the stronger foot. This gives you more homework, but you can build strength and develop two strong feet.
Go to a ballet store during quiet shopping hours if possible. Call them first and let them know you want to come in and talk to someone who knows the shoe inventory, and can help you. Ask a lot of questions before the shoe fitter brings out shoes.
If you have hyper-mobile feet with a high arch, you'll need stronger shanks, probably a longer vamp, though not if your toes are short.
Let the shoe fitter see you on demi pointe - she/he will hopefully see right away the length of your toes, the type of arch you have, your foot width, and will know what shoes to suggest.
Your teacher may give you an idea of what shoes to try on as well.
Try on the shoes with your tights on your feet, and also wear some padding - be it gel or lambswool or a tissue wrapped around your toes - this will help you get as close to exactly the right fit as possible. Don't make it a goal to get rid of padding. As you get stronger you may use less or none, but don't assume you will never need it.
Do not try to stretch the life of your pointe shoes with extra padding - that will not work, and you may get injured. Pouring shellac into the shoe can add some extra life, if done before they are worn out. But you need to experiment with this, and have a good pair of shoes to wear to class while you try out shellacking another pair. Without practice, you cannot count on this to work out well.
Ultimately, if you have good practice routines to continue building strength for ballet and pointe work, you can avoid dancing in pain. Taking care of your feet involves strength, gentle stretches for some of you, foot massage and supportive street shoes. Work like a pro, right now.
Make sure you know about pointe shoe sizing, to avoid dancing in pain.