Answer:
When I get closer my tail grows longer but when I go away my tail leads the way.
People buy me to eat but never eat me. What am I?
When you need me, you must find me. When you find me, you no longer need me. What am I?
I go through a door but never go in, and never come out. What am I?
I am of several different kinds, but the one you pick doesn't do its job. What am I?
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.