There are very few limits to working with senior citizens. Working for the city parks department, I was fingerprinted, and my background checked, although I doubt that they were worried that I might be selling drugs to seniors. It was mostly a formality in working for the city. Unless you are calling yourself a therapist or some official title, you won't have much in the way of limits restricting you. You will want to show that you have a love of the art you are doing and a love of sharing it with people. You will need to show patience and tolerance for the handicaps that many seniors endure. I doubt that a racist or an intolerant person who doesn't like people speaking Spanish or some other language than English will get very far with the seniors. Other than that, enjoy the process.