I first used the Internet as a public user in 1988/89, which I believe is about its earliest use. Prior to this it was known at ARPANET and used by a small group of universities and government defense agencies for easy exchange of information. Likewise, email in it's current form developed along side domain name registration and it was just becoming something commericial companies considered as possibly useful. As a graduate student at the time, I was able to do get useful research done by going to university websites, which were hardly more than lists of files available under a webserver.
World wide web invented by Sir Tim Berners Lee - then set up 1st website 1991, made available to all in 1993. Needless to say his creation was gigantic.
Commercial internet service providers began to offer services in about 1989, including "Software Tool and Die", which still exists as "std.com" and claims to be "the world's first dialup internet service."