"Terraforming" is kind of similar to nanobots, in that it's an entirely theoretical concept pop-sci plebeians like Blob think is inevitable and an answer to all our current problems.
I'm not an expert in extraterrestrial geology or meteorology but terraforming the Moon presents a billion questions with basically no answer. For starters its soil is irradiated to shit because of billions of years of near direct exposure to the Sun. The Moon does have an atmosphere, but it's incredibly thin and for all intents and purposes it's nonexistent. It's got roughly a fifth of the Earth's gravity which presents all sorts of engineering problems for farming. It's got extreme temperatures in both directions because again, basically no fucking atmosphere. Water does exist on the Moon but not in any way to make the soil fertile. You'd have to mine it, essentially.
You could theoretically construct large-scale terrariums which create an artificial Earth-like atmosphere. Kind of like in The Moon is a Harsh Mistress. You'd have to import soil from the Earth though. And it doesn't solve the gravity situation, but frankly that's pretty low on the list of reasons why growing shit on the Moon is near impossible.
The best candidates for creating sustainable farms are Mars and Venus. Mars because it's got a decently thick atmosphere and a considerable amount of water. Venus because it's upper atmosphere is remarkably similar to Earth's, and Cloud City-style floating colonies on Venus actually are very feasible. Much more so than growing wheat on the fucking Moon.