I'm not old enough to have used an acoustic coupler, but I do remember the 1200 baud modem that was NOT Hayes compatible. You had to dial the number yourself, and push a button on the modem to connect once you heard the tones. When I was little, this was connected to a VT100 terminal -- green text on black. I eventually learned to use this terminal to dial into BBSes.
I was into BBSing for a number of years, even joined FidoNet at one point. I was a member of a fairly large BBS (they had twelve phone lines!) which also had an internet connection, and this was my first experience with internet services like gopher and telnet. They had a text-based web connection too but it was so slow and frustrating that I gave up quickly.
In 1995, I did a co-op term at a company that had its own dedicated ISDN line -- a huge 128 kbps pipe that was shared across the entire company. I don't recall the very first website I visited, but Yahoo and IMDB were certainly among the first. I learned HTML that fall and did a lot of work converting Word documents to HTML by hand for the company intranet. Everyone was saying that if I knew HTML, I'd have a very marketable skill that would land me all kinds of high-paying jobs... I was even hired by the school librarian to tutor her son for $15/hour so he could get in on this too. I even went so far as to start writing a book to teach HTML to students. Too bad I never finished, I might actually have been one of the earlier books published before the market got completely flooded.