2007 400ex not starting

hey everyone i was out riding yesterday and i stoped at a buddys house and sat there and talked with him for awhile and i when i was leaving leaving i went to start my quad and it just clicked from the seliond so we jumped the selioned and it started but when i tried to use the electric start the neutral light would go out and i would have no headlights. and when we jumped the seliond it just would turn the bike over until it sounded like it was going to start then start clicking again so i dont know what is a matter with it . i cleaned the termanials and conncetions but i dont even know where to start looking for the problem at

Thanks everyone