Just walk in and say hello and introduce yourself. Eg: "Hello I'm LacyGreen. I'll be your student nurse today and I need to check your vitals." Or something to that effect. Biggest thing in my experience (CNA, just started LPN program) is to be confident in what you are doing and stay relaxed. If you are nervous and show it, the client is usually quick to pick up on that and may be uncomfortable with you.