Well you need to buy some freons! R134a should be good, you can get that @ kragen or autozone. You're also going to need a pressure gauge for when you charge it into the car.
1. Connect the r134 into your pressure gauge
2. Connect the r134 into the low pressure gauge in your car, it should be in front of the exhaust manifold.
3. Turn on your car and activate your a/c.
4. your car should gradually suck in the new freons.
5. After you're done charging disconnect the lines and keep your car running for a good 10 mins just to break in the newwww freons.
6. You should be set after this.
7. I hope this helped you bro.
8. good luck!