No, although pineapple fish and parrot fish are tropical fish, but the parrot fish will eat the pineapple fish,

But to mix from a young age the chances of success are not great (I especially want to ask the science teacher's qq to ask)

You can, but pineapple fish or parrot fish a need to be covered with a plastic bag for a day or two, otherwise it will fight (this answer has a mistake, covered with a plastic bag for a day or two = not mixed)