How to fix a car air conditioner?

I have a 2001 ford taurus and last time I put some of the air conditioning suppliments in the car it lasted about 5 minutes so I think theirs a leak in a tube or something I don't know much about cars but want to get started so I can get a car fixing career going on and this will be my first project. So what do you guys think I should do is it a leak and if it is what should I replace?

So yeah, your car's AC clearly has a leak, so you need to bring to a qualified auto mechanic skilled in AC repair. A car's AC other than adding freon substitute is not something you can do at home.