How do I make a tutorial for my game?

How would I make it so the user can only click on one thing, like a button, and everything else darkens like on regular tutorials for other games?

You can use the fade behaviour to fade an objects opacity to 75% then have something like text above it:

Here is a demo I put together:

dropbox.com/s/ks0wsld0ybgng84/Tutorial.c3p

Thanks