The best use of male plants is to fertilize female ones.
Second best use for male hemp plants is to cut them down for FIBER, same as any other hemp plant! I'm guessing you aren't growing for fiber.
You can't make hemp oil from male plants, since the oil (better known as hempseed oil) is made by pressing seeds.
Contrary to popular belief, male plants sometimes do have a good bit of THC in the growing TOPS (only), especially if the male is from a super-potent strain. Males also develop higher concentrations of THC early in their growth cycle right after flowering. If you've got nothing else, it may well be worth cutting, curing and smoking the leaves from the top few inches of the plant, especially the young growing ones. You may well be surprised at the results.
Along those lines, it definitely is possible to make hash oil or cannabutter from male plants (again, you'd want to use the tops), but I think you'd need quite a few of them before trying it would be worthwhile. I probably wouldn't bother with just one small plant.