Learning a new skill in the times of lockdown is essential. Everybody who has access to a decent internet should opt-in for learning a new skill so they can better present themselves to the world and make money when the COVID-19 dilemma is over.
Many websites are focusing on providing free skills. Many famous MOOC websites have already made their high-priced, premium courses free (thanks to the instructors for saving mankind) so people can benefit and learn new skills from home.
Open Culture is one of the best repositories for high quality cultural as well as educational mediums. The site is not affiliated with any university and all submissions are of their writers in private terms.
Here is a list of more than 1500 courses offered by more than 1000 universities and colleges across the globe for all disciplines. These courses are free to use however if you change the course then you might be charged. This list is tabulated by an open culture and provides one of kind resource for people who are stuck in isolation.
From Standford to Yale, MIT or even Oxford, this is a comprehensive list that not only mentions who teaches it but also provides a link directly to the course of the resource.