How do you level up your pokemon?
Points differ on how well you answer it.

Poffin Uses: At 100% performance an Oran Berry will produce a level 10 Dry Poffin when cooking alone.

You level up your Pokemon by battling other Pokemon and defeating them, which makes you gain experience. When that Pokemon gains a certain amount of experience, it will grow a level. A Pokemon reaches it's peak of experience points when it reaches level 100. You can also level up your Pokemon by giving it a Rare Candy, which makes the Pokemon grow one level. Other items that help are the Lucky Egg, which lets you gain extra experience in battle, and the EXP. Share, which gives a portion of experience to another Pokemon that didn't participate in the battle.

2 points for the 1st, 3 points for the second.
5 in total.

Next question coming soon.

As well as the Lucky Egg and the Exp Share, a traded pokemon gains a boost in experience each time it battles so it levels up much quicker and can be harder to control.

And just a note, but I might not be popping in as often as I usually do. o.o