Can we turn a fixie bike into a freewheeler? I'm new to the fixie world. I'm planning to buy a fixie bike though, but to start right away would be difficult especially when I'm pedaling down hill. Is it possible to change the fixie bike into the freewheeler with both front and back brakes?

Please HELP!
You can buy a flip hub rear wheel where one side is fixed, the other free (Some bikes even come with them). You just take the wheel off, flip sides and put it back on. Brakes will depend on the frame but most frames allow for the installation of brakes. For the rear brake, you'll just have run full cable housing along the frame with either wire ties or cable clamps.