Yes. Go to route 5 where you first met Alder, Cheren will speak to you and then leave. He can then be found near the end of Victory Road, for rematches.
You can find Cheren in Victory Road before you go to the Pokemon Leage
The elite four, the champion, (Cheren, Bianca,you have to find them)and,(Cynthia,after you beat the game)
Oshawott is available as a starter Pokemon in the game. If you do not choose it as your starter, either Bianca or Cheren will have it.
After you battle Cheren at Twist Mountain, Alder will give it to you as part of the plot.
Fennel is in the building nearest to the striaton gym.
You can't find rayquaza in pokemon platinum.
You can get surf in Pokemon black and white by battling Cheren at the Twisted Mountain. Then Champion Alder will give both you can Cheren th HM Surf.
Alder gives it to you after battling Cheren after earning your 6th gym badge
The elite four, the champion, (Cheren, Bianca,you have to find them)and,(Cynthia,after you beat the game)
Cheren is in the last room of Victory Road before going to Victory Road. (Meet him on Route 5 first.) Bianca is in Professor Juniper's Lab. (I think after beating Alder, I'm not sure)
you can find it in pinwheel forest after beating the elite 4 (.)(.)
you can't. there could be an event in the future or something
You find N in N's castle in Victory Road.
After you beat Ghatsis on Black or White, you cannot find him again.
Oshawott is available as a starter Pokemon in the game. If you do not choose it as your starter, either Bianca or Cheren will have it.
After you battle Cheren at Twist Mountain, Alder will give it to you as part of the plot.
beat Cynthia at undella town complete unova and national pokedex get dive and go into the abyssal ruins at undella bay find the seven sages and find and beat cheren and bianca one more time.
The cave cave u take to go to go to the Pokemon League