There are tons of free resources dedicated for machine learning. Difficult to choose from.
I found this video lectures interesting as starting point: https://www.youtube.com/watch?v=Gv9_4yMHFhI&list=PLblh5JKOoLUICTaGLRoHQDuF_7q2GfuJF
Most of the concepts discussed in these videos are too introductory for economics graduates, but a good review before starting machine learning journey. I strongly suggest to watch this video.
I will have a list with pros and cons and a final recommendation here: