First used: In high school (1976), an HP 2000G school district machine running BASIC, via 300-baud ASR33 teletype with paper tape reader/punch.
First owned: In college (1978), an IBM 1620 which the school gave me in lieu of scrapping it. I still have it, and AFAIK it's the last operational one in the world. Serial number 98, originally bought by Pettijohn Engineering, then donated to Vernonia High School when Pettijohn got an 1130, then donated to University of Portland (where the paper tape reader was interfaced to a PDP-8/e), then me.