Do I need to have a food hygiene qualification / certificate to serve food to the public?

The law requires that you are appropriately supervised, instructed or trained in food safety matters, bearing in mind the kind of work that you do. 

This may mean that you have obtained experience in other jobs that can be useful, or it may mean you have to go on an accredited course.  You can obtain information about courses in your area by visiting The Chartered Institute of Environmental Health.