I am before the league and I need help with my team. I don't know which..

You are going to have a heck of a time trying to beat the elite four. Personally, I couldn't do it with those Pokemon without lots of full restores.

I recommend training all of your Pokemon to at LEAST level 40. The key to beating the elite four is having a variety of Pokemon types. That way, you can use super effective moves to make the battles easier.

Here is a list of some good types to have.

Fire
Grass
Water
Fighting
Electric
Psychic

So base your Pokemon selection around that. You have a grass Pokemon (Sceptile), a good psychic Pokemon that I used was Gardevior (Ralts evolved twice), and some good fire Pokemon can be found in Fiery Path. Be creative

And for move sets, remove crap moves like Screech, Rock Smash, and Detect. They don't do much. Add stronger moves and you should be fine.

First level up your Pokemon to 70, then evolve Vulpix to ninetale's....You will need a water type and electric type with you so get one aswell...go back and post your team when you've done what I told you to do..then I will give move set's that suit's them fine...i'm sure you don't have a cheat device so that's fine...TM's i'm going to give you can be bought on the poke shop's.

Id say you need to train most of the Pokemon a little more before you can win