To get all Pokemon without using the Game Boy Advance Pokemon games, Nintendo WiFi is needed. In Jubilife City is a Worldwide Trade Station. Go in and talk to a person at the desk; say "Yes" to everything. You will then be in a strange looking place. You will automatically go to a computer where you can search for the Pokemon you want. However, you must to trade a Pokemon they want to get the Pokemon you want. Easy National Dex Pokemon: To easily get National Dex Pokemon, visit Lucas' or Dawn's little sister in Sandgem Town. Every day she will tell you where a certain National Dex Pokemon is swarming at a certain route. There is different Pokemon information every day. Easy experience: To easily gain experience, spend money on any desired item. Then, go to the Pokemon League and fight the Elite Four until you lose. You will have gained, then lost a small amount of money, but your Pokemon might have leveled up. If not, level up. You can buy a lot of Revives and Potions to use to get to the last of the Elite Four and they might just be level up. Hatching eggs quickly: If you have a Pokemon with the Magma Armor or Flame Body ability in your party, it will cut the hatch time in half.
If you have a Pokemon egg and are waiting for it to hatch, it will hatch after 10,250 steps. The best place to get a lot of steps is in Amity Square. By doing this, you are able to collect something from the Pokemon that you are walking after every 200 steps.
In Solaceon Town, get on the far right side of the path next to the Pokecenter. Then, ride your bike in the fastest gear up and down until you hit a tree or mountain and repeat. You must have done at least 400 steps each "lap" to get an egg to hatch more quickly.