First Computer: Commodore PET. First program sold in 1979 to this chap from Kalle Infotec, to help him sell this exciting new concept called the Fax machine.
First got online in 1985 at Cambridge, and got linked using GROGGS and of course MUD and for multiplayer networked action games, Bolo.
First Usenet post Jan 1st 1994.
First website probably in 1996ish, though I'd put togther an offline HyperText system incorporating images, video, sound and text markup for a group of Veterinarians in 1992.