Stick to bottled water.
Tagine is the local hot food which can be found everywhere It is slow cooked for hours under a conical lid. There are meats with vegetables or vegetarian and they are always delicious.
Vegetarian and vegan foods are available with lots of salads, nuts, couscous and fruits etc.
Gluten free is a little trickier but you should find the locals more than willing to prepare something special.
Moroccans love tea which is usually mint or a type of green tea. It always come loaded with sugar. Coffee is available everywhere but black tea is only Lipton's Yellow Label so bring your own.
Some hotels sell alcohol and the local Moroccan wine and beer is very good but it is not widely available in shops.