The first check I ever wrote from my own account was June 13, 1985. My aunt and I were going to Redwoods National Park that summer and I had my other aunt who lived in CA make campground reservations for us. So I reimbursed her for the campground fees.
I have posted many times that my furriness exploded in 1985. I rented my first fursuit for Halloween (found the receipt!) and started buying every anthropomorphic comic I possibly could. On Dec 1 I wrote a check to Steve Gallacci to get as many issues of "Albedo" as I possibly could. I should bring the check to cons and hope that he's there. He might get a kick out of seeing it.
Speaking of comics...I found several checks to various comic book companies. I had subscriptions to "Critters" as well as many Disney titles like "Rescue Rangers" and "Tail Spin." I also bought Gladstone titles with Donald Duck and Mickey Mouse. One interesting check was to Bob Burden since I fell in love with "Flaming Carrot Comics" in 1988. Does that make me a "veggie?" He also created "The Mystery Men." What was neat was the cancelled check had his signature.
The only other interesting checks were to my various landlords. So what was I paying in rent back then? I lived in a trailer in grad school. I must have been a polar bear back then because I would have been white bear trash. *lol* My trailer cost $189/mo. This was fine since my TA pay was about $500/mo. I briefly rented another trailer when I was turning in my thesis. That was $240/mo. When I got my first long-term job in Yakima, I briefly had a 2-bedroom place for $445 a month. Then I found a 2-bedroom house for $400/mo. Pictures of the apartment and the house can be found here from an LJ post in 2012 when I made a roadtrip to Rainfurest.