I just went to libraries and asked my friends for information.
By the way, the internet didn't suddenly become filled with all the knowledge in the world. The first internet pages were like personal blogs filled with not-so-useful information. In those days, the internet was similar to today's darknet. Google was just starting out, and there was no search engine as such. As a result, people just shared websites with each other. The current internet is the result of millions of people's efforts to fill it with information. So, having access to the internet didn't change my life overnight.
But we used to buy collections of websites and data on CDs when CD-ROMs first became available, and that was pretty fun.
UPD: and at some point, people started exchanging data through modem calls, and that's how fidonet was born. It was a whole cultural layer where you could get an address and slowly receive newsletters and exchange data through late-night calls to sisops. It was like a prehistoric torrent, but instead of pirating, you were exchanging data.