Answer:
I am often sold by children entrepreneurs in summer time
I move without wings between silken strings. I leave as you find my substance behind
I am a shiny metal sheet that covers BBQ food.
I dig out tiny caves and store gold and silver in them. I also build bridges of silver and make crowns of gold. Sooner or later everybody needs my help yet many people are afraid to let me help them.
I go up, let out a load and then go back down. What am I?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?