The printer arrived on Tuesday and by Friday I had a small bin of plastic that used to be other shapes. Everyone warned me about this. They were right, and I still didn't listen properly.
Almost every failure was the first layer. Too high and the lines never bond, so you get a loose nest of spaghetti that the nozzle then drags around the bed. Too low and the filament has nowhere to go, so it smears, the extruder skips, and you spend ten minutes wondering why nothing is coming out. The fix isn't clever, it's just patience: a sheet of paper under the nozzle, level each corner, then print one of those single-layer test squares and watch it like a hawk.
The benchy came out on the fourth attempt and I was absurdly pleased with a small plastic boat. It's lumpy. It leans slightly to port. I'm keeping it on the desk anyway, because it's the first thing this machine made that I didn't have to peel off and apologise to.
The actual lesson is the boring one. The printer wasn't the problem and neither was the slicer. I was, every time, by rushing the bed levelling because I wanted to see it go. Slow is smooth, smooth is a benchy.