I have a follow-up question after finishing the first course of the specialization: where shall I experiment a bit with real (albeit small) problems? Is there a platform or catalogue of data sources to play with? Maybe some problems with also their best model solution?
Kaggle is a good place to start. It hosts thousands of datasets perfect for practicing both regression and classification, ranging from beginner-friendly (like the Titanic or Housing Price datasets) to advanced real-world problems.