>>542948923
Tickets are basically the number one priority to buy with mana prisms. The fous are probably second highest priority. EXP is good too, but you can farm those infinitely outside of the shop so only buy them if you've got a surplus of mana prisms or are in a rush to level someone.

If you're lacking mana prisms that's normal, the best source for those will be in lotto events. Our next lotto event is in December, and honestly you'll want to save every single apple you get for it since lottos are invaluable for new players and we only have one lotto next year (as opposed to the usual two lottos we get per year).