Im shy how can gain confidence to my self and how to overcome this

Remember names - you need to remember everybody's name. All the people you've met and talked to, the next time you see them, greet them with their name. People will feel more comfortable around you which makes the interaction with them more pleasant and easy. Also, when you say bye to them, use their name.

Remember something unique about them. If you remember something unique about the person which you've talked to, ask them about it the next time you see them. They will like you more and like to talk to you more.

Ask them about themselves - ask people questions that aren't too intrusive. Anything about them that you are genuinely interested in, ask them about it. People love talking about themselves :).

If you do these things, people will feel more comfortable around you, thus decreasing the probability for you to be shy. These actions will help improve your confidence as well as help you improve your social skills. It also helps if you greet people frequently, like when you pass by them in the hall at work or school. The next time that you feel shy about something, realize that other people in the same situation will feel the same way. I hope this helps.

A.K.