What should I do for Halloween?

So, I'm at that age where I am too old to Trick-or-Treat (I am nineteen), but I don't really have anything else to do. I don't want to go out to party (I don't even know of any parties around where I live.) And my best friends are handing out candy at their grandparents house without me. I was planning on hanging out with them, but now that they have plans, I don't know what to do. Handing out candy really isn't my thing, but I don't want to not celebrate Halloween at all, either. Any suggestions? I also don't have a costume, so anything dressing up wise is kinda out of the question..