There were lots of little niche forums where you could find a lot of different perspectives. I remember as a kid going to nuklearpower.com, the home of the 8-Bit theater webcomic, and I found a thread in the forums about religion and it was kind of my first real exposure to ideas about it outside of what I'd been raised to believe.

Most early memes were lolcats or epic fails, and I remember going through pages and pages on cheezburger.com with my friends. There were also "demotivational posters," like this was the height of comedy.

4chan existed and was pretty bad even then but it was more common for somewhat normal people to go there, they loved their slurs and gross out humor but it wasn't full nazi, it was edgy teens. In general slurs and homophobia were a lot more common, but a lot of the edgy, "you can't tell me what to do" energy was directed at the religious right, the "moral guardians" who wanted to take away your violent video games. The left was very weak and didn't have the sort of cultural presence it has today, instead you had a lot of energy directed towards libertarianism, with Ron Paul being the anti-war, pro-weed candidate, and you had liberals with ACLU type values. Things weren't cut as neatly along party lines back then.

Fewer people were on the internet back then. Lots of young people used it but not as many boomers. There weren't as many big pillars like Facebook/Twitter/Reddit, there were more subcultures and you never quite knew what you'd find (for better or worse). Algorithms were a lot less polished and you didn't have as much SEO, Youtube looked and felt radically different.

The indie game Secret Little Haven captures some of the feel of that time period of the internet, from the perspective of a transfem, it gets heavy but it's good.