what were they doing for food?

Nothing apparently. They didnt even showed them eating too much.

Same as for clothes and other items. Waiting for the caterers and prop people.

It's described in the novel that the troupe is fed by the communities it visits as a form of payment for the entertainment. In addition, the members hunt and go into the woods and harvest wild fruits and veggies. Most of the world's population is killed off by the virus so there is an abundance.The show does show them growing food at the airport and people hunting.