SIGGRAPH University has presentations, lectures and course videos. Khan Academy has a series called Pixar in a Box about CG in film production. It covers a lot of terminology from graphics programming in an entertaining format. Here are some other free online courses available: Coursera - Interactive Computer Graphics, edX Computer Graphics, Stanford CS 148, Brown CS 123.
Definitely check out the Real-Time Rendering Resourses site, it has a very comprehensive set of links, pointers and recommendations. (kudos to Eric H!)
It's great that you're checking out Godot it has a really vibrant community. Getting hands on and building things will propel you. There is a TON of descriptive material, learning resources and sample projects available at the Unity and Unreal developer training sites.
Don't go it alone. Seek out the blogs and forums that interest you and dive in. It's a large body of knowledge with new techniques and terminology cropping up everyday. Enjoy!