i am very enthusiastic about MOOC, thousands of online courses that are free (some you can pay to get an actual certificate on completion)
uni's all over the world provide them, even cambridge!
https://www.classcentral.com/course/edx-re-conceiving-space-installation-and-performance-art-21289
https://www.edx.org/search?q=art%20history%20&tab=course
https://www.coursera.org/learn/contemporary-art