Explore, catch pokemon, trade between Firered, Leafgreen, ruby, and sapphire, and go to Nintendo events. I think that you can get some from colosseum, but not sure.
I believe you can trade or get Pokemon from Colosseun or Pokemon XD but I think you need to beat the main story line in one of the games first. It has been awhile since I did it but the proof is that my togepi is no longer in XD or Colosseum. For its box location it just says missing so I figured I must have traded it over. I did it 2 years ago so I don't remember.
You find them in poke balls every once in a while.
Yes. Every single Pokemon from every Pokemon Game is part of the National Pokedex
There is no Wonder News in Pokemon FireRed, whatever that is.
no it does not. the games for the ds will have it
You can't go to Johto in Pokemon FireRed or LeafGreen.
No.
every where
Battle every trainer and Trade with Pokemon colleseum
No you don't have to. But if you want every Pokemon you must.
you can get every pokemon using codes you can get legendary pokemon such as mew regi's HO-OH Lugia every kind of pokemon
get every Pokemon in the game then go to mystery cave and catch it
the hospitals are Pokemon centers there the red buildings in every town
Walk around. That's how it is in every Pokemon game. How could you not know that?
Pretty much every cave.
There is no "best" Pokemon because every Pokemon has its own weaknesses and strengths against other types of Pokemon,
In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
in every game its wild exept for leafgreen and firered you have to trade a Pokemon to get it