Mid century full bed will find homemade full size platform beds easy to construct if you know how to measure and sawn timber. You also need to know how to drill holes and how to both insert and countersunk screws so that you can securely fasten the boards. You will basically build a large box that will sit up and down so the mattress can rest on top of that platform.
Poplar or forest birch makes good choice to build a frame. These easily accessible forests look well colored or painted, and they are available in different widths and lengths. Full size bed mattresses measure 54 inches long by 75 inches wide, and if you choose to make your platform larger to account overhang or to make room for a built-in bedside table.
If you are building a mid century full bed with a 4-inch rim at the outer edge, start with two hardwood planks measuring 75 inches long for the sides of your home-made bed, as well as five hardwood planks measuring 58 inches long for the top and bottom frames and the center supporting your bed. Use discs measuring 2 inches thick and 8 inches wide. The side boards will butt against the top and bottom frame boards, getting the extra 4 inches from the thickness of these two boards. Fill the platform bed with a plywood plate to fit over the top of your box frame. Use metal L brackets to build the frame and connect the support beams, and wood screws to attach the plywood to the frame.