MOOCs（Massive Open Online Courses ）is a model for delivering learning content online to any person who wants to take a course. And also with no limit on attendance.
Most contents are made with English. Therefore, it is necessary for you(and me) to understand English to enjoy this massive and rich knowledge.
I recommend you to start with the course "From the Big Bang to Dark Energy" on the web site below.
https://www.coursera.org/course/bigbang
Hitoshi Murayama is a Professor of Physics, University of California Berkeley, The University of Tokyo. Though there is a recommended "high school level basic physics knowledge are required to fully understand the course content" .
But it seems to be not so difficult, because he wrote some books for pepole, 「宇宙は何でできているのか (幻冬舎新書) 」and others.
There are many contents to be available free in MOOCS. Let's enjoy it!
（人材育成社）