Well you either give it a stone or evolve it in pokemon pearl in the ice place or the eterna forest!
To make Eevee evolve into a Vaporeon, you have to expose it to a Water Stone.
To make Eevee evolve into a Flareon, you have to expose it to a Fire Stone.
You have to make Eevee really happy while it's is evolving,there is no certain level that will make Eevee evolve.
use a firestone on eevee
You can't make eevee evolve into espeon by leveling it up. You have to give it a certain stone. I think it might be a moonstone, but maybe that makes eevee evolve into umbreon.
To make Eevee evolve into an Umbreon, you have to level it up with high happiness at night.
evolve it with happiness and make the evolution start at night
in the morning, after 8:00, you evolve eevee into espeon, at night, after 8:00, it evoles into umbreon (make sure eevee likes you alot)
When Eevee loves you, level it up in the Morning.
Eevee can not evolve into porygon.
No, Eevee does not have to evolve to breed.
eevee can only evolve once but if you get another eevee (of different gender )and breed with it you can get another eevee and evolve it into something else.