You an train Pokemon in the grass
train your pokemon
you train them
Yes, you can
Train a Chansey and will evolve.
Get a Golbat and train it.
ANYWHERE
You can't find "strong Pokemon". If you want a Pokemon to be strong, you need to train it.
No you have to train surskit to level 22.
Train a mudkip to level 36.
Keep battling the Elite Four it really trains your Pokemon!! That's how I train my Pokemon. Either that or an Action Replay, which I have...
train some electric Pokemon or just level up your Pokemon loads
Take a fighting type or train your Pokemon more