Fresh stuff - fruit & veg, solid meat, fish, rice, dairy are generally all ok. Things likely to contain gluten are processed eg mince meat, sauces, bakery products, anything with wheat. If you check on your supermarket shelf many types of products do have some gluten free in the selection. It is written on the label if it is gluten free. There are also lots of recipes avaiable on the internet.
"Unknowingly, we plow the dust of the stars, blown about us by the wind, and drink the universe in a glass of rain."