Try to buy the food you want to eat in a supermarket and cook it in your apartment.
If you want to go out for lunch or dinner, Souk Wakif is the best option!
For the transportation, Uber is cheap, but Careem is most cheaper;)
But I really recommend you to go by Metro, very fast, safe and cheap!
We got information about prices in Doha on food in cafes and restaurants, products in supermarkets, accommodation rental and transportation costs based on the data of 5 people.
We analyzed the average prices in Doha and calculated that one day in city will cost you 732 Qatari rials.