Well, the point of work experience is for you to *experience* what the realities of your chosen occupation is. And if you haven't chosen one (which is often the rule, not the exception!), make a list of jobs that you are interested in. Anything that you could on day see yourself doing, or that falls within your fields of interests.
Like travelling? Try working at an airport of travel agency.
Interested in the outdoors? Spend a week tailing a park ranger, or work a nursery. You get the idea.
Me, I am a classically trained musician, and am working towards becoming a music therapist. My first round of work experience was shadowing a music therapist at a major hospital.
My whole family is in medicine, so I also did stint at a pharmacy, but that wasn't so great, because it wasn't really what I was interested in. It has got to be something you want to do.
Another time I did work experience at a radion station (now, that was fun!), which was closer to my interests.
So, make up your list, and think of all the jobs you could do. If it helps, perhaps come back here and tell us your interests, and we'll gladly throw up some ideas for you.