I'm a boy and I walk strange?

Barcode is right as usual but I would like you to consider consulting a podiatrist and a physiotherapist as they are the people who deal with your type of problem, all day, every day. You might simply have learned a bad gait but from what you say, I suspect that you have problems that would greatly benefit from a professional consultation. A lot of people's legs are of different lengths; a millimetre will not matter but 10 millimetres will change your gait. If a particular tendon in your feet is tight, you will tend to walk, in a toe-down-first manner.