Your attunement will happen anyway, whatever you are doing, but you will probably want to find your own way of making it something special to remember. You don't have to be on your own, either. You might want to be with your family or a friend, or you can hold a pet or a favourite toy. Once you have had your attunement, all you need to do is place your hands on yourself, another person, an animal or a plant and the Reiki will start to work on healing. You may feel nothing at all, or your hands may feel a bit warmer or cooler than usual, or they might feel a bit tingly.
Different people feel different things.
Reiki is useful for many things and can never hurt in any way. Feel free to experiment with different uses for Reiki. So long as you act in a loving and caring way, you can't go wrong. You might want to keep a diary or journal of your experiences with Reiki. Reiki goes to where it thinks is best.