The way I learned was looking at scripts, look at what they do, and then I just kept doing that.
A basic one be:
After you typed "/test" in-game, you would then say "blahblahblah". Then after another 5 seconds you would say "blahblahblah" again. You'll probably need to talk to a person that's better at CubeScript than me :P
A basic one be:
[SELECT ALL] Code:
test = [say "blahblahblah"; sleep 5000 [say blahblahblah]]
After you typed "/test" in-game, you would then say "blahblahblah". Then after another 5 seconds you would say "blahblahblah" again. You'll probably need to talk to a person that's better at CubeScript than me :P