Check out Hillsdale College. They offer a free course on the Constitution online.
There are several different courses the Hillsdale offers free on line. The lectures are informative and (mostly) easy to follow. I’ve read and referred to the Federalist Papers on more than one occasion and thought I was pretty well informed on the Constitution. I barely got passing grades on the first two tests I took on Hillsdale. I’ve gone back and learned to listen rather than try to do two things at once, as I am inclined to do.