I'm assuming you mean coeliac disease. . . gluten is found in wheat. So you will need to be avoiding all wheat based products. Bread, cakes, cereals and biscuits are obvious, but loads of pre-packed products could trip you up!
If you live in the uk there are loads of gluten free products clearly labelled as such in supermarkets like Sainsburys and Tesco. Also Boots hold a more limited stock. If your GP or specialist hasn't provided you with dietary advice i would think you will find sites on the internet and details of support groups.
Any dietary changes are difficult at first but it soon becomes habitual.
Best Of Luck!! 