You can't get him dehorned at that age....well technically you CAN, but it will be very painful for him and there is a chance he could bleed out and die if not done properly.
With or without horns, he'll still have the attitude. While horns will make it hurt more, your problem is not his horns. It's that he is aggressive. For starters, he's a buck. Unless you plan on breeding, which I dont assume/suggest you do at this point since you're new to goats, he needs to be cut. At this age banding is out of the question since he is fully developed down there. So you'll need to get him surgically castrated.
You say there are no local vets, well that is true of many places. I have to drive 2 hours to see a good goat vet. It's part of life with animals. Just look around and I'm sure you will find a place within 2 hours of you that does castration. Its a pretty basic procedure.
Another thing, you have him by himself. Goats need to be kept with another goat, preferably 2 or more. The more goats the happier they are. That is a fact. Since he is by himself he is lonely and sees you as part of the herd. This is dangerous thinking, since you are the owner and are not in fact part of the herd, you are the boss of the herd. If they see you as part of the herd they will want to challenge you to make sure they have their place above you in the pecking order. So you need to remind them that you are the boss, and not to be challenged. Many people do this by hitting the goat or shoving it. DONT do that. That reinforces their thinking that you are, in fact, a part of their herd. Since another goat would react in a similar way. What i do is I grab them tightly by their collar and just say NO. That way, it enforces the fact that I have control over them, but in a non violent way. I have heard other people spray them with water. One of my goats is really dependent on humans and calls whenever someone walks by. So what I did was when she tried to challenge me I simply walked away. She got really upset no one was there paying attention to her and I think she learned her lesson.