Map nerds are doing incredible things. New technologies are still evolving.
Here are some map and map-making resources that I have explored.
NOT GOOGLE MAPS / SIRI
OpenStreetMap.org - has a lot. Created by people like you. Open license.
There is a good guide to using OSM at missingmaps.org
maps.stamen.com - easy and elegant map tiles.
PRIVATE COLLECTORS HAVE GREAT COLLECTIONS
David Rumsey Map Collection - "Cartography Associates" with an incredible collection of freely downloadable high quality map scans.
Stanford Earthworks - has more maps
THE GOVERNMENT HAS CONTINUOUSLY ACQUIRED AND DISTRIBUTED PUBLIC INFORMATION FOR YOU
(but any megopolis probably has a similar regional dataset)
Association of Bay Area Governments - Data, Maps, Apps
Association of Bay Area Governments - Open Data - Resiliency Program / Natural Hazards
RESOURCES FOR MAKING GIS / VECTOR MAPS
QGIS (Q is for 'quantum') is an open source Geographical Information System. There is a growing community of map nerds working with this, and a good deal of documentation. There's definitely a learning curve, but it is a powerful tool if you can find your way around. I import public data maps --> select the content I need --> export a SVG file --> style it in Adobe Illustrator (you could also use Affinity Designer, etc.).
Topologically Integrated Geographic Encoding and Referencing — a digital database of geographic features, such as roads, railroads, rivers, lakes, legal boundaries, census statistical boundaries, etc.
United States only. Not as precise as some other map sets.
Natural Earth - vector and raster for basic earth features, no borders.