Especially the chalk-like stroked food icons
well for me, when you have chosen ur size, create the vector art background you want to use. so if it is a group of icons or vector art you want to create them and put them together. you can get vector art from freepik.com
i will advice drawing a rectangle over the artboard shape, add the preferred color and then lock the rectangle, so it doesnt move.
for the art u what to use as the background group them together and make a copy and then merge that copy to form 1 design.
place it over the rectangle and then go to properties and reduce the opacity to prefered level.
i believe that should get you started