As a domain expert, you’d probably want to focus specifically on feature engineering if you’re looking to continue training the existing model or new models. A lot of it comes down to asking good questions and hypothesis testing informed by knowledge of the law that you already have.

Figuring out how to use those models in real-world applications employs a different skillset, however, and that sounds more like what your original question is asking about. You’d probably get a better sense of this through examples of applications that intro to ML courses reference and surveying ML-driven applications in various industries. Here's a good hands-on resource: https://machinelearningmastery.com/start-here