It might sound a bit old fashioned, but is there a toastmasters chapter near you [1]? It's an organisation dedicated to improving public speaking, but it's actually a lot of fun.
The first half of the meeting is where people give prepared speeches and get evaluated. The second half people have to give a 2 minute talk on an improvised topic.
You'll meet people in a supportive and friendly environment, improve a useful skill, and have lots of fun.