I completely agree with @janbb. The world has plenty of talkers and not enough listeners. I would encourage you to focus your energy on maintaining eye contact and really listening to what the other speaker is saying.
Teddy Roosevelt said that when he knew he was going to meet someone, he would read three books on subjects that he knew interested the other person so that he could hold up his half of a conversation.
I used to be very awkward in the type of situation you described and now I am very comfortable. Learning to listen is a big part of it, but listening also gives you a chance to observe speakers to see what works, what hand gestures do they use, what facial expressions accompany their words, etc. Over time, you will naturally incorporate certain effective techniques if you study them in this way. Next time you watch TV, don’t look at the show, watch what the actors do to convey various elements of what they are trying to say. You will start to get that it is much more than the words that come out of your mouth.
The other big thing is topics. If you want to talk about things that no one in the room cares about, don’t bother. You need to become familiar with topics that are of interest to others. For example, I train dogs for search and rescue. Many folks watch CSI and other police procedurals on TV, so they are very curious about search dogs, (e.g., Do the dogs live with you? How do you train a dog to find a dead body? Do you work with the police, etc). When people are asking you questions about something they think is interesting, different or curious, it is very easy to be the life of the party just by answering the questions on topics other people find interesting and about which they know little.