Can you take real courses online for free?
Yes, and the catalog is bigger than most people think. Khan Academy is entirely free, on edX and Coursera you can audit nearly all university courses without a certificate, and platforms like Codecademy and DataCamp have free starter tiers.
The best free route is the audit model on the university platforms. On edX and Coursera you can follow most courses completely free: you watch every lecture and read all the material, but you get no certificate and sometimes no graded work. If you want to learn rather than collect paper, that is everything you need.
Khan Academy deserves its own mention: a nonprofit where literally everything is free, with mastery-based practice from school math up through economics and computing. For foundations, there is nothing better at any price. For technical skills, Codecademy and DataCamp offer free starter tiers that teach you the basics before you spend a cent.
The honest nuance: free learning demands more discipline. Without a paid plan or deadline, quitting is easy. If you notice yourself stalling, a small subscription can work precisely as the commitment device.