While not free, one of the best values going is a subscription to The Great Courses Plus. With the subscription, you can access hundreds college level and high school level courses of just about any topic you can imagine, as well as special interest courses such as cooking, photography, writing, and even how to play musical instruments.
A number of these courses are fully appropriate for CPE, and I have used them more than once for my own, especially on topics in privacy and legal aspects.
Some of their courses are based on partnerships with The Smithsonian, History Channel, Culinary Institute of America, Mayo Clinic, and National Geographic.
You can use a single subscription on up to five devices, so the whole family can use it.
They have a streaming app (Apple TV, Google Play, iOS/iPadOS, Roku, Kindle Fire, Chromecast, Amazon fire TV), so I watch class sessions on my big TV with my Roku stick (one of my five).
I have also talked to residents of retirement communities who gather in a common room on a schedule to the courses from GC+ as a group. (OK, these days sit 6 ft / 2m apart.)