Jupyter Notebooks
If you want to learn from a practical example, please, take a look at the following Jupyter Notebook: Jupyter Notebook - Introduction to the SpatioTemporal Asset Catalog (STAC).
This jupyter notebook will explain step by step how to use the STAC client library to retrieve metadata and access the image collections or data cube collections.
More examples regarding how to use STAC and a few applications can be found on Jupyter Notebook - Image processing on images obtained through STAC.