This is tough to answer because it's of course politically convoluted. Currently, we have the Outer Space Treaty and the Moon Treaty, but while OST seems more formal, the Moon Treaty is really more of a gentlemen's agreements and not ratified by any major space-faring nation.
So in reality, there is currently no globally agreed on legislation regarding exploitation of lunar resources. United Nations Office for Outer Space Affairs (UNOOSA) seems a fair bit more active in the last few years and there's all kinds of other public forums and organisations dealing with this subject, all trying to eventually draft proposals that would be acceptable to the international community and ratified before we really start industrializing the Moon.
So, for the time being and according to OST, as long as you're using the Moon for peaceful purposes, don't place weapons of mass destruction on it, and don't interfere with peaceful exploration of it by other nations, there is no international legislation standing in your way to do so. But since other nations might have different views than yours, make sure you establish a dialog regarding your intentions first, because you'll meet with opposition here on Earth, if they for some reason don't like what you're doing up there on the Moon.