First, there is a mountain of information at www.relayforlife.org I can tell you what I have been involved with. I am a Hero of HOpe Speaker for the American Cancer society, and relay for life. You will understand most of this better if you look at the website and read the history of Relay, why it started, who started it, it's meaning, and how people raise funds. But, in a small nutshell:
You can join a team and help them with the fundraisers that they already have going on to learn. This is best so you can learn under their guidance. YOu can start a team or be a one person team, or friends and family team. You conduct fundraisers like car wash, bake sale, entertainment event, road blocks, send out letters and emails asking for donations,etc. Again, lots of information and ideas for fundraisers on the website.
I would contact your local relay for life chapter and introduce yourself, tell them you are a survivor and they will welcome you with open arms, and invite you to the event as an honorary guest to walk in the survivor lap, and to come to the survivor dinner as a guest. Then you can tell the event chair, person in charge, that you want to volunteer. They will put you in touch with a team that can mentor you and you can help. Win=win.
The idea behind relay is that it is an overnight event. The setting sun represents the patient receiving the diagnoses. The middle of the night represents the long hard treatments and tough times we have in treatment, the time when many think they cannot go on. Similarly, the person walking the track all night might think they cannot go on. Then the sun rising represents the finishing of treatment, and beginning of recovery. so staying all night is symbolic. But you do not have to, the dedicated teams do.
Let me know if you have more questions I am happy to help.