Man...I didn't even know the internet existed in the early 90s (junior high). I can't remember when I first used it...in high school and it was so slow that I didn't care for it.
However, I do remember using
and acroynms in my grade 10 computer class (93/92). Not on the internet though.
I know it wasn't popular at the company I work for now in the mid 90s.