Of course, there is the 'catch 22' for inexperienced performers... the nerves are bad because of lack of experience, but how can you gain the experience to combat the nerves...!

Some are luckier than others, because they learn to cope fairly quickly. I'm fairly sure that I learned to combat nerves by being part of a trio in the early days, and only went solo after I'd quite a few gigs under my belt. That was forty years ago...!!

It's a warm feeling when you realise you are immersed in what you are doing, and the audience are totally with you. Choice of material is so important - I really hate it when a performer is so obviously 'doing' songs from a list rather than singing from the heart. Sincerity is so important, as an audience sees straight through an insincere performance.

If you can find a 'daft' song that's also quite clever, it can be a useful icebreaker, but, as others have already commented, you have to be able to do it without thinking.