I am an experienced dev, who learned about all the marvelous FLOSS tooling, by randomling stumbling upon it in deep dives into Linux ecosystem. And I have no i

I am an experienced dev, who learned about all the marvelous FLOSS tooling, by randomling stumbling upon it in deep dives into Linux ecosystem. And I have no idea how it could be even remotely possible for a youngling to discover the same things in the torrent of sloppy SaaS. Do you know of a "hitchikers guide to the FLOSS galaxy" that could teach the ways of the elders, from the ground up?