You don't get to start a completely unprovoked and illegal war of aggression, bomb tons of targets with little care, kill 100 schoolchildren, and then say, "But it was a mistake."
And however much you can say about the current US Administration, I don't think they're prioritizing bombing civilians over military targets.
The US is bombing both military and civilian targets, by the way. Trump has been very open about this with his talk about "power-plant day." He considers attacking civilian targets to be a legitimate way of pressuring Iran to surrender.
And administration repeatedly threatened to destroy civilian targets.