I believe Togepi evolves around 40ish. He alos has to liek you so don't let him die an' give him lots of items an' haircuts. He may evolve sooner.
The leader in Goldenrod isn't so hard. She is if you have really low level monsters. I suggest only carryin' a pary of maybe 3 at most in the beggining. Keep them roughly the same level. Get yur Pokes to level 30, at least a couple, then try to beat the gym. If any monster should be higher level than the rest, make it your starter until you have legendaries.
Also, who was yur starter? This makes a difference too.
Baby I like it.