There are more and more MakeCode examples available every day. I've listed some of my favorites in the sidebar, and there are new ones being added almost every week. Just search "MakeCode" in the Learn System search bar to dive in.

Also, check out John Park's MakeCode Minute YouTube Series for more tips and tricks than you can shake a stick at. 

Have fun making things light up, and post lots of pictures of your costumes!