The best way to overcome a lack of social skills is with practice. Keep in mind, however, that not everyone can be the life of the party. Some of us are naturally comfortable conversing with others. This way you are sure to get a chance to contribute to the conversation. If the thought of socializing with just one individual makes you uncomfortable, then I suggest practicing conversing online.
Chats are very convenient ways to communicate with others.
When you're comfortable with talking to one person, move on to larger groups. Tag along with a couple friends to a party. Parties are great places for meeting new people and socializing. Don't over-examine what you're saying. If you monitor every little thing you say, then chances are you will miss your opportunity to say what you wanted to say in the first place.