Building a bench doesn't have to be hard. This is a 2'x8' "torsion beam" design where the beam is just three nailed and glued 2x4's. If you mount presses through the beam with long carriage bolts, the resistance to movement and twisting is phenomenal.
This picture shows end 2x4's screwed on to the single 2x4 legs to stiffen and strengthen them....and keep them from ever kicking out.
Because the torsion beam takes all the stress, the top only needs to be one 3/4" plywood top, fastened down with screws to the beam and the 2x4 support screwed to the wall. It doesn't even need cross supports because subtracting the beam (4.5") and the back support (1.5") you only have 18" in between...you're not going to notice any flex at all with 3/4" plywood screwed down and spanning 18", even if you put something heavy on it....ok, like a tool box full of wrenches that takes two men to lift that high.
Material and cut list below except for the plywood top. Have Home Depot rip your plywood top to give you a 24" wide piece, then rip what's left to make two 12"-ish shelves.
The picture below is such a bench garnished with an optional drawer stack (admittedly a little more skill involved), and 2 extra 2x4's at each leg (with quarter round moulding to fancy up the joints)
A 1x2 face was nailed on around the top once formica was glued down and trimmed flush against the edge of the plywood. My presses were mounted first, and the face trim was fit around them, to have minimal projection in the room. My carriage bolts sometimes were drilled between the beam 2x4's which is why you want to glue the laminations....plus I use very large fender washers below to spread the load to the rest of the beam. Worked really well.
Next drawing attempts to show how the legs were prettied up.
The best part about this design is that you can find an old drafting stool and reload sitting or standing, since there is "knee" space under the bench. It's a simple matter to nail a shelf underneath, but as you can see from my photo, the shelf is recessessed, to preserve the knee space.