Well, I haven't spent much time on Menewsha, but on Gaia, I usually hold holiday event threads.
Such as a Halloween one, with costume contests and giveaways.

Is there somewhere on Menewsha that I could create something like that?
Is that sort of a thread even allowed?

I would wager it belongs here since it's a contest thread/give away.

http://www.menewsha.com/forum/commun...sts-giveaways/

We've got a contests forum over in Community Discussion that you could put it in.
Or, alternatively, you can post them in the relevant event forum during an event. :)

:3 alright~ thanks guys, I'll do that.

Or you could wait until the actual Halloween/other holiday event forum is open and host it there. :) Depends on how far in advance of an event you want to hold it.