Three suggestions:
1) you could start with Alexis Van Hurkman's book
Color Correction Handbook: Professional Techniques for Video and Cinema. Lots of very useful information in there.
2) the
International Colorist Academy does have classes in major cities around the world on various platforms, including Resolve, Baselight, Scratch, and Nucoda. But this is only a class that goes three or four days.
3)
FXPHD has some online tutorials that go through the basics.
Color-correction is an art that takes thousands of hours to learn. I've done it for decades, and I still learn new things in every session, particularly from the directors and DPs I work with. It's not something you can get overnight, and it's a long process -- not unlike sound mixing, visual effects, or cinematography. You may eventually realize it's better, faster, and cheaper to hire an expert than do it yourself.
Even Robert Rodriguez, who famously writes, produces, directs, edits, lights, operates the camera, supervises visual effects, and writes music for many of his own films, chooses not to color-correct his films. He supervises them, but doesn't do the work himself.