How do you sound proof a room without spending to much money?

Question

where you make it to where you dont hear outside noises, and its completely silent in your room

Answer 1

cork is a good insulator.  that is why they use it in sound studios.  you can get in 12 inch  squares or off a roll.

Answer 2

Buy some noise-reducing headphones.   $1.99 at Harbor Freight.   Even cheaper, foam ear inserts, $.59 anywhere.

For a slightly more expensive solution, get a white noise generator.  $50-80.