you go in the room 2nd to the right
You go to the bottom floor of the Pokemon centre, HOWEVER you need to have friend codes to actually battle
Yes, you can, my friend has both of thoose games and he has copied Pokemon on it and did ds battleing against me. (I kicked his butt though!!)
No. Any battle that is a Battle Tower or Linked battle will NOT count towards your Pokedex, unfortunately.
That depends on what Pokemon your friend uses and their movesets. Since you didn't specify this, my advice to you is to find counter-Pokemon and strategies to your friend's Pokemon. It takes more than just good Pokemon to win a battle.
you don't need a friend code to battle and trade people. you just need a friend with a ds (and a pokemon game) and Internet (optional). with another friend you can do whatever you want. with Internet you can go to the gts and trade pokemon.
You go to the bottom floor of the Pokemon centre, HOWEVER you need to have friend codes to actually battle
Yes you do need a friend code to battle on wifi
yes
Yes, you can.
Make sure SoulSilver has Platinum's Friend Code, and Platinum has SoulSilver's Friend Code.
yes you can
go to the union room with a friend
You can't. You have to get Pokemon SoulSilver if you would like the red orb or trade with a friend. The red orb is only obtainable in Pokemon SoulSilver.
Trade with a friend who has diamond ,pearl ,or platinum.
i would trade one with a friend who has porygon on their game
You trade Pokemon from Pokemon Heartgold and Soulsilver to Pokemon Diamond by going to the wifi room in the Pokemon center on the top floor. You also need to have a copy of Pokemon Diamond and have to have a friend or someone who has a copy of Pokemon Heartgold or Soulsilver. You will see someone there if you are going to trade with someone. Talk to the person you are going to trade with and ask them if they want to trade. The top floor is the Union Room no Friend Code needed the basement is the Wi-fi room, which requires a Friend codes
Migrate from Ruby, Sapphire, Or Emrald. Or trade from a friend