As you head up, you will find you need to head right. Just next to the far right stairs you will see an item ball which contains a Potion. Head up the stairs. The boy at the top of them tells you that running with your shoes will attract the attention of nearby trainers and wild Pokemon. Just beyond this person is a building. The man tells you that people usually come to his house looking for Mr. Pokemon's house. He asks if you meant to visit his house. He asks if you have any apricorns. He explains the trees bear fruit once a day. He remarks he has one (the tree on the left side of his house). These fruits can be made into Pokeballs and other things. He is happy to have met you, feeling that fate was behind it, he gives you an Apricorn Box, which you can use to store apricorns. Head out of the house. Check the tree, hitting “a”. Your character will shake the tree and get a Grn Apricorn. Head to the right of the house and continue upwards.
Going up, you will see an item ball on the left side. It has an antidote inside it. Just above that, you will see a sign, and a few people. The closest person to you explains how, as long as a move has PP, a Pokemon can use it. When it has no more PP, it cannot be used and you should take your Pokemon to a Pokemon Center. The person above him, just to the left is battling someone and will not move at all. Looks like you need to do things until they finish.
Keep to the right side and keep going up to reach Mr. Pokemon's House. There is an Apricorn Tree next to this house, which gives you a Pnk Apricorn. Head inside to meet Mr. Pokemon.
When you go in, you find he was expecting you. He pulls you in and gives you a Mystery Egg to pass onto Prof. Elm. He gives you a moment to rest your Pokemon. Then, Mr. Pokemon's friend, Professor Oak, will chime in, noting the care you have taken of your Pokemon, and ask you to help him with his project, the Pokedex. His goal is to document all of the Pokemon in the world.