I lived my formative years long before the Internet. I was 47 or 48 before I first went on-line, and that was fairly early for where I lived, as the first Internet café of our city opened up right across the street. And even then, there wasn't much information gathering on line as such. I did start finding stories though and later imagery, especially on venues like the alt.sex.enemas bulletin boards.
My main sources of information before the Internet were books and magazines. Luckily where I live there have always been lots of bookstores, secondhand bookstores and stores willing to sell sex material. Even if we had to go to the Netherlands in the late 1960s and 1970s. There were sex shops galore in the small border villages and they all sold magazines of all types in all languages - English, Dutch, German, Danish, Swedish. You could find just about anything.
Secondhand bookstores were also a good venue for finding material, often in the form of secondhand medical textbooks, though these stores sold anything and everything and used to be very open minded. Being in large cities, there were also many such shops, some specializing in this or that, sex material included. I was and still am an inveterate collector and always visited any flea market or secondhand store that I came across, and I often found many an interesting item. Flea markets in France often yielded many an irrigation device. I've found many beauties in the most unlikely of places.
Back in pre Internet times, building up a collection of material and stuff was harder to do than now and once something was lost, almost impossible to replace. That went for simple items like books too - no amazon or eBay back then. So you learned to take care and if necessary, carefully hide it as well, especially when still living at home with your parents ... 😃 😃.