if you are not familiar with edx.org, check it out. Free classes on almost anything you can think of. These courses are taught by professors from major universities around the US such as MIT, Yale, Harvard, Colorado School of Mines, Corenell, Brown, etc etc. These are the same classes being taught there, give to you, for free.
Coming up are the following rocket related courses.
From Goddard to Apollo: The History of Rockets, Part 1 Self Paced.
https://www.edx.org/course/goddard-apollo-history-rockets-part-1-ieeex-atg1-x-0
The Conquest of Space: Space Exploration and Rocket Science. (startet Feb 9th but you can catch up):
https://www.edx.org/course/conquest-space-space-exploration-rocket-uc3mx-bia-1x
Introduction to Aerospace Engineering: Astronautics and Human Spaceflight. TBA (I’ve taken this course, it is great!
https://www.edx.org/course/introduction-aerospace-engineering-mitx-16-00x