There are free online courses available from many accredited online universities. You don't need to be enrolled in a particular university to take the courses, and they're free for anyone who has an interest in them.
These online courses are offered through platforms such as Coursera and edX; the lectures and class materials are recorded and transcribed for the benefit of those enrolled. The application process is simple, with no prerequisites; you just make an account and enroll. The courses are mostly lectures with short quizzes at the end of the lecture to test comprehension. The professors might also offer a final assignment for the course. There are deadlines as well, but the deadlines are lenient, taking into account that most people who take these online courses might not have the time to be enrolled even part-time at a university.
It's also easy to communicate with the professors to clarify doubts, as the courses usually have websites and forums, and instructors can be reached by email. The students enrolled in online courses can also communicate with one another and share their gained knowledge on the class forums. After completion of an online course, a certificate of completion is granted to those who passed.