how can i get a new charger for free

You have to buy, no one wil give you a free charger.

You don’t. And what do you call a “charger”? The thing you plug into the wall, or the cable that connects that thingy to your phone? Actually, neither is a charger; the charger is in the phone. One is a power source, and the other is a wire to move energy from the power source to the phone. Both are available from almost any supermarket or gas station.

Accessories come with a one year warranty. If your charger is older than a year, you'll need to buy one. You can buy a charger from Apple, from BestBuy or even on Amazon or Staples.