First of all, this is NOT meant for the Strategies & Movesets section of the forums. Next time, post things like this in the Simple Questions thread, mkay?
Getting a Pokemon to have the necessary happiness at low levels is difficult and taxing. Besides the usual grooming done by the haircut brothers in the underground and May, a Pokemon usually gains happiness by leveling up. I don't recall if there's a hold item in 2nd gen that makes Pokemon friendlier, like the Soothe Bell in the 3rd gen. Unless you're willing to wait day after day to raise that Eevee's happiness via grooming, I suggest that you just level it up and be satisfied with a medium-level Espeon, since it doesn't really learn any decent level-up moves before level 36. Anything before that (Tackle, Tail Whip, Sand Attack, Confusion, Quick Attack, and Swift) aren't really worth the trouble.
