My first pond... well, I've always loved water, mud, frogs, fish, salamanders, etc. An old couple (late 80s) across the street, had a concrete goldfish pond that I visited, with permission, and helped around it. When they moved to a simpler living style, they offered the goldfish, just 3 or 4 to me. I must have been about 10 at the time. Mom was a biology major, so encouraged my plan. We got a concrete double washtub and with dad's help, sunk it in the ground, after a really careful cleaning. Filled, with a few plants from their pond, we let it sit for a week, then moved the fish in. They did fine for a year, then some local teenage trouble makers decided to come in while we were gone and pour oil on the pond. We came home to very dead fish. The to boys were caught and slapped on the wrist. Oh well.
I moved to aquariums for a few years, then back to ponds.