Answer:
Curtail me thrice I am a youth; behead me once a snake; complete I'm often used in truth when certain steps you'd take.
You turn me over after you have travelled far.
I have a brother. However much we run we do not reach each other.
you hold my tail while I fish for you
I am a vegetable that bugs stay away from
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.