I am not a carpenter or master wood worker by any means, but the minimum tools you would need to build a canopy is a circular saw, a drill, and a bunch of clamps. You will also need a reliable tape measure, wood glue and screws. Other useful tools would be a jig saw or hand saw to cut out things like vents and fan openings, and a speed square to help mark your cuts on the wood (but these are not absolutely needed).
I would frame the canopy out of 1x2 pine, and skin it with 1/2 inch plywood of whatever type of wood you like. Glue and screw everything together. Then you can add decorative trim to pretty it up. Trim can be attached simply with wood glue and clamps.