Playing at an old people's home is a good start but the novelty will soon wear off when you realise you're not getting any applause because they're all deaf! Open mic sessions are the logical place to play as you will gain the experience of being plugged-in and learning microphone technique. On stage it will sound totally different to anything you've done before as you probably won't be able to hear yourself properly, especially without stage monitors. But it's all valuable experience and you will learn to enjoy your new found frienships as well. Good luck.