Firstly, what is shyness? One definition is a feeling of the fear of embarrassment. Perhaps more fully it can be defined as a feeling of apprehension or awkwardness experienced when a person is in proximity to other people, especially in unfamiliar situations.
It sums up to a lack of confidence. Behind this is a fear of what others may think of us. Is it not said commonly that shyness is the natural enemy of confidence? With good reason. The shy can find themselves being held back in life. A little shyness in the form of modesty is an attractive attribute and shows you are not an overwhelming extrovert. However, if you follow the above definitions and summations your shyness will prevent you from clearly communicating with people, face to face, on the phone or even in writing. It stops you from being outwardly confident with new acquaintances. You will not stand out, you will not impress, at least in a positive way. As such you could miss being offered opportunities that could advance you.
Is it then just bad luck to be born shy? No, it is not. It is an environmental influence that some naturally fall into, but it is not genetic. You can remove these inhibitions if you decide to do so and have a bit of will and discipline to change, to stop regarding yourself as naturally shy.
The way we regard ourselves is by assigning an identity that is outwardly expressed by our appearance and actions and inwardly by assigning emotions and thoughts to our identity. Done constantly, by habit, then we take our identity to be an unchangeable truth. We fall into the trap of acting in a certain way by falling into the trap of believing we are that way.
So, how to overcome shyness? If we can assign a shy identity to ourselves does it not stand to reason that we can conversely assign a more outgoing identity? Avoid thinking that you are unchangeable. Consider that you can transform yourself across a mental border from the shy side to the outgoing person side. Use imagination to see yourself in a situation where you are confident, where you are not afraid of what others think of you. Where you are not shy.
Realise that you need not be afraid of what others may think. If you do stumble out the wrong words and your belief is that the other guy will laugh at you, forever, then remove this belief. The reality is that he will not laugh. The other guy may not even realise, and for sure, he probably has his own issues along these lines to even care of your apparent mistakes. You need not worry.
There are methods to help you mentally define this reality and to remove your fear, but for now the imagination will do well. Imagine confidence, imagine other people, with an open mind, as people who are not out to intimidate you. Eventually you will see the reality and then naturally dismiss shyness.