The first computer I ever used was a Dell Pentium 1 running Windows 95 with AutoCAD 13. This was at my first job after Architecture school where I had only drafted with pencil and paper (and ink and mylar ).
At home, I had a used Compaq Prolinea (386 I think) that I found in a thrift store for $20.00. This was before the internet, so I had to drive across town to find a math co-processor for it to run AutoCAD 12 DOS, which was also purchased used from a store that only sold second-hand software. This was my introduction to tinkering with old computers.