Kids built projects out of magazines,
The better ones like "Radio Television & Hobbies" (formerly "Radio & Hobbies".later "Electronics Australia") gave circuit operation descriptions.
RTV & H also had a lot of basic theory articles.
We also voraciously read books --ARRL Handbooks,RSGB Manuals,& so on.
Some authors of Electronics books had great names,like Fink,Chinn,Scroggie & other whimsical sounding monikers.
There was usually a older friend or relative into such things who would loan,or gift older versions.
We made Radios---- hobbyists commonly had a better understanding of Superheterodyne principles than some folks asking (& answering) questions on this forum.
Audio amplifiers were also common projects,back when HIFI was a "Geek" hobby.
Many people of that period had the ability to "visualise" the operation of circuitry---an ability which seems far less evident these days.
Electronics was BIG--enthusiasts usually found ,if not Apprenticeships,counrter & store jobs with local Electronics shops.
To increase their knowledge,many attended Technical College night school classes.
My first "hands-on" experience with an Oscilloscope was at around 13 when my brother brought a little 2" AWA 'scope home from work.
It was fascinating injecting random mains hum into the vertical input & watching the "wiggly lines".
Next time was at Perth Tech School,where they had Cossor 'scopes.
When I got a real Technical job (at 22),I was amazed by the wondrous Tek 545 & similar,but didn't get to play with them.
That job fell through,& in the next we had 5" AWA & EMI 'scopes,with fairly poor bandwidth,& a 5MHZ Serviscope.
We hardly ever used them.
Then I was sent to a TV Transmitter site with a 545B which was used regularly.
What a nightmare learning how to use the Delayed timebase !
My first private 'scope was when I was about 29----just a collectors item,really,as it was a 2" Philips which looked almost identical to that little AWA of so many years before.
My first
really useable private 'scope was a BWD which I bought secondhand in the late 1980s.