Property is theft.
Every anarchist knows this.
Property rights come from gov't. If it weren't for gov't, you would not be able to lay claim to what is the common heritage of all. So how does your nonaggression principal reconcile with exclusive deed to what would not be yours if the gov't did not exist to give it to you?
Good question. I'll answer it for you.
Original occupation of unowned and unoccupied property is one way.
Voluntary exchange of one thing for another thing, is another way.
I have some turnips, you have some cheetohs. Must a central government, who isn't us, be present to oversee our exchange of property or could we do it peacefully without them ? Yes, of course we could. Well maybe not you and me, but two peaceful people could. You'd skew it because your currency is tainted as it wasn't justly acquired....but you get the idea.
Was government necessary for me to "create" the turnip ? The answer is clearly, no.