I attended a 'local' event last night and recognised some of the comments made above - if you sing your own song(s) it really helps if you consider a brief explanation of the song/story and remember to sing clearly so your audience can understand your words and the sentiment of the song. A nervous performer played his guitar well but unfortunately mumbled his way through words and made me jump when, at the end of the song he used the 'mike' to say a very loud 'thankyou'. Had he only used the mike and clear diction I'm sure I would have enjoyed his performance more. Audiences are 'forgiving' and recognise newcomers nerves but like Shimrod said above, don't make it go on and on.
Whatever you do Dg, enjoy your performances.