Google Earth Pro is a free software that, albeit not a true GIS, allows visualization, assessment, overlay, and creation of geospatial data. This user-friendly resource is often a useful intermediary for learners who are interested in learning more about GIS and want to start with more basic processes and tools. Google Earth Pro can also be leveraged to view its extremely high-resolution satellite imagery, upload or download geospatial data in its native interoperable fileformat (KML), and also find locations (e.g. for simple geocoding).
Google Earth home - https://www.google.com/earth/
Launch Google Earth Pro on the Web - https://earth.google.com/web/
Download Google Earth Pro for Desktop - https://www.google.com/earth/versions/
Google Earth Engine provides access to high-resolution satellite imagery, geospatial datasets, planetary-scale analysis capabilities for scientists, researchers, and developers to detect changes, map trends, and quantify differences on the Earth's surface.
Explore Google Earth Engine: https://earthengine.google.com/
Google Earth Outreach (Google)
This series of step-by-step tutorials, offered through Google itself, gives a great starting point to get the most out of Google Earth Pro: https://www.google.com/earth/outreach/learn/.
Google Earth Pro: A tutorial (University of Waterloo)
The University of Waterloo has made available this 16-page PDF tutorial that introduces learners to Google Earth Pro: https://uwaterloo.ca/library/geospatial/sites/ca.library.geospatial/files/uploads/files/google_earth_2016.pdf.
Google Earth (YouTube)
YouTube is another great source for "how-to" videos on Google Earth Pro: https://www.youtube.com/results?search_query=google+earth+pro.
Google Earth Blog (Google)
Check out this official Google Earth Blog to get a better sense of what you can do with this resource and for inspiration: https://www.blog.google/products/earth/.