As mentioned by many PPs, gluten free and wheat free are not the same - GF food can have de-glutenised wheat in it.
Many things that should be safe have a “may contain” warning on the package - these are not safe eg oats, lentils etc are often processed on the same machinery or alongside wheat products, hence the chance for cross contamination.
For takeaways, check your local chippy, many do GF fish & chips on the day that the oil is changed.
at our local Indian, all the vegetable dishes, all the Tandoori dishes and many of the curries are wheat free. I would not eat poppadoms even though they are what free as often fried in the same oil as samosas etc. Same with Onion bhaji, gram flour is GF and a kind friend often makes me a batch of her delicious ones.
chinese food is more difficult, due to soy sauce used in marinades, and cross contamination in fryers, although our local (expensive) sit down Chinese does an excellent GF menu
Nando’s are good, with clear labelling and information
Thai food can be good but will depend on the outlet, same with Japanese, just watch out for soy sauce in marinades.
best pizza I’ve had is from Zizzi, Most others very cardboardy, even Pizza Express. Or White Rabbit GF pizza from supermarket frozen section.
if it’s Gluten you will also need to avoid barley, rye and oats - so GF beer only, GF oats etc.
jacket potatoes or omelettes are good for lunch out and about, most supermarket sandwiches are terrible. Some soup can be ok but again you will need to check.
good luck!