You can use an all day pass on the bus for 4,50$.
On food, the best and cheapest places are Burguer King, la lechonera, cuban café and supermarkets like Aldi, la chiquita or Fancy fruits.
For a place to stay in, i use Airbnb but if you don't feel comfortable using an app, you can check for hotels outside downtown disney and you will find rooms from 20$ to whatever the price you need.
We got information about prices in Orlando on food in cafes and restaurants, products in supermarkets, accommodation rental and transportation costs based on the data of 1 person.