All Pokemon evolve differently.
Here's a breeding key (scroll down when you get there)
http://www.serebii.net/pokedex-rs/
Keep capturing pokemons, and train your pokemons so they evolve and become a new, similar pokemon.
after catching all the pokemons
You can't evolve Yanma in Leafgreen. This is because Leafgreen was made before Yanmega was made. So basically in Leafgreen, Yanma is a Pokemon that can't evolve.
you cannot evolve a porygon2 in leafgreen
Piloswine does not evolve in LeafGreen. It didn't get an evolution until Diamond/Pearl/Platinum, which came out after LeafGreen.
You can't on leafgreen.
In a rare occasion, you can find them in the safari, in Fuchsia City.
Articuno, Zapdos, moultress and Ho oh.
he has to be lv 40, then he will evolve.
It must be traded to evolve.
No.
No.