If you just want a low cost sump with no bells and whistles; you can use any of the square opaque containers that are available at the Home Centers. You will need to drill the sump if you plan to use a non-submersable return pump. You will need an overflow and flexable hose for waterflow to the sump. Now this is as simple as it can get. But most likely, you will have problems with it because of your lack of experience.
But here is what you really should do:
Most reef stores have display tanks with sumps inside the cabinet. look closely at them and note the equipment that is in them and how the sump is constructed. Look at how the water flows from the tank to the sump.
Join a local reef club. They are an excellent way to to see first hand how the members built their sumps.
or if you can find a fish store that sells them, then take a look.