Many people are uncomfortable mingling during business networking or other public events. Are you one who is often worried about what people will think of you? The easiest way to get around that is to put our focus on “them”. How? First of all, look for people who appear somewhat lonely, standing by themselves. They will appreciate you coming up to them and initiating a conversation. This helps get relationship-building 
conversations started while promoting confidence in yourself and them. It is easier to join a group previously engaged in a discussion after someone leaves, breaking the circle of participants, which then allow us to comfortably slip right in. The following guidelines will also help:
People approach when your back is to the light, such as standing in front of a window during the daytime
Keep your posture erect, palms up with arms and fingers open and a friendly smile that invites conversation.
Always hold your beverage in your “left” hand to avoid a wet and clammy handshake.
Be mindful that the best conversationalists are the ones with the best “active listening” skills! Let them talk 60% of the time. Reflect back to them tidbits of what they said to show you “heard” them.
Introductions can be confusing so here is an easy way to confidently introduce two people:
Introduce the person with the “least important” title (regardless of gender) to the person with the most important title. For example: Mr. or Ms. Greater Authority, I would like to introduce you to Mr. or Ms. Lesser Authority. An example is introducing a company president’s name before a sales representative. When introducing someone to an individual from another company, however, the one with the “highest position” is actually the guest, or client…even if he/she holds “lower” title.
Introductions should be brief. “How do you do?” or “Hello” is fine. If you can’t remember someone’s name, reintroduce yourself and they will often say their name again. If they don’t, say something like, “We met at last month’s marketing conference at the Embassy Suites. I’m (name).” They should offer it to you at that point. If they still don’t, just smile and say, “I apologize. Would you give me your name again please?”
The main point to remember is: lean slightly forward,positive and confident posture, give a warm handshake, smile and be totally sincere and engaged in getting to know them and what they do! That kind of interest will have them wanting to get to know you better as well. Enjoy!!
https://www.selfgrowth.com/articles/introductions-and-mingling-how-do-i-conduct-myself