You cannot get the HM for Strength without going to Nimbasa City.
You need to first make it to nimbasa city. Then, you go to the top left house WITHOUT going up the stairs, and talk to the guy at the table.
YOu get strength by going to the top-left building in Nimbasa city
You get it by going to nimbasa city and going into a house in the upper left part of the city.
u get zorua by using the relocater to transfer celebi and go to a building in nimbasa city and zorua will be in a illuzion. u get zoroark by going east of nimbasa city with the three legendary dog pokemon. they must be shiny
You must beat the eliet 4 and then beat N and Getsis to finish the story, you can get to the transfer lab by going to the right out of Nimbasa city
White Forest (or, in Pokémon Black Version, Black City) is located east of Nimbasa City. Fly to Nimbasa and take the eastern entrance into Route 16. Just keep going east and you'll get to Marvelous Bridge. Cross Marvelous Bridge and you'll arrive at Route 15. Keep going east, and you'll find White Forest/Black City. Basically just go to Nimbasa and keep heading east. Hope this helps.
Rival
Yes, once you complete the game, you can access the PokeTransfer lab, which will let you migrate Pokemon to Black/White, from Diamond/Pearl/Platinum, HG and SS. But you're going to need another DS system. The PokeLab is around the route right of Nimbasa city.
It mean's the Pokemon your going to battle will ether be your same strength or stronger
The subway in nimbasa. take the 4th train going clockwise
Well, first your going to have to obtain the Strength HM. Assuming you have that, teach it to a pokemon. Press A on the boulder you want to move and walk in whatever direction you want it to move.
I'm pretty sure you can just talk to a breeder in Nimbasa City Beat Her Get a Rare Candy Exiting Going Back in Beat Her get a Rare Candy On and On hi cutie