Sounds like you are off to a good start. If you have any questions about QGIS check out the QGIS US - OSGeo Discourse category. Lots of QGIS folks there ready to answer questions. @rjhale1971 runs a QGIS Meeting that I think meets every two weeks or so - the last one was this - Virtual QGIS Meeting May 19th 2026 - 12:00 EDT - #2 by rjhale1971.
On the PostGIS side, I wrote the most popular book on PostGIS - PostGIS in Action, Third Edition - Leo S. Hsu and Regina O. Obe and I’m working on a PostgreSQL book PostgreSQL: Up and Running, 4th Edition [Book] . As far as PostGIS help goes, we have a PostGIS mailing list, matrix chat change - which are listed here - Chat | PostGIS and Mailing Lists | PostGIS which you can find me hanging out in.