you have to go to prof oak and get rock climb and then get to the top of mount silver and battle red. he has Pokemon level 80-90 about so he is not easy.
Go to the Kanto region and try to beat their 8 gym leaders.
After you've beaten Brock go beat the other six leaders then you can fight Blue
I know that in soul silver, after you beat all 16 gym leaders the professor gives it to you.
cerulean cave after you beat all the gym leaders
I do not know where he is after beating elite four soul silver. I hope to find him soon.
beat the all the gym leaders
beat the elite four.
Go to the Kanto region and try to beat their 8 gym leaders.
After you've beaten Brock go beat the other six leaders then you can fight Blue
professor elm will give it to you once you beat all the gym leaders in the Jhoto
im pretty sure you gotta beat red then the rest of the gym leaders
I know that in soul silver, after you beat all 16 gym leaders the professor gives it to you.
you got to beat all the Pokemon gym leaders in kanto other then blue,then talk to him
After beating Brock, if you haven't faced the other Gym leaders yet, go challenge them.
Beat all the Johto gym leaders and the Kimono Girls. (They're in Ecuteark city.)
Re
beat the battle frontier, collect every gym leaders pokegear number and beat them at level 100. then your done. also get mewtwo in cerulean cave.