It’s a big subject you might need to narrow it down a little! some machine learning topics include:-
- Big data
- Assisted leaning (nerual.networks)
- Machine vision
- Anomaly detection
- Fraud detection
You can then think about particularly frameworks such as Apache spark, tensors flow, torch.
Amazon have a number of services and associated learning resources.
To be honest you could be looking at an entire degree just for the foundation. I have a compsci background and I only have a vague understanding. So most the resources of will be academic ones from universities.
If you just want a light hearted, vague concept then I love code bullet A.I. LEARNS to Play Hill Climb Racing - YouTube .
I’m not sure how education it is but he covers some of the learning concepts and shows the networks as his AI learns to play games. He is also entertaining.
Testing wise none of the background really matters you just need data set or scenarios for testing. The same as you would for any testing anything.