Lifelong Windows user here, starting at 3.1. I could have had an early-ish Mac for free in the mid-nineties when the IT dept scrapped various machines they'd tried. They went with Windows, the Mac probably to landfill...
I didn't get my hands on a Mac until a couple of years ago, when I got hold of a Mac Pro 2,1. Start at the top, why not?
Swapped that for a big Win server which I stripped. Then recently bought, spares or repair, a 27" 2009 Core 2 Duo iMac. There was absolutely zero wrong with it, which I'd worked out from the ad, it just needed the faff of making a proper USB boot disk to do a clean install. Bingo, working machine.
Then a couple of weeks ago, I got another Mac Pro, a 3,1, for £20, VGC original box and manual included but no drives. So now I have as much Apple iron as I do Windows!