How do you know which ones to press when you are restraining and trying..

Well, there's a pattern going on, and you won't be able to restrain or cheer up the sim without memorizing it. For example, when you're trying to cheer them up, and they stick their arms out, they want a hug. Or when they're crying you're supposed to console. Just pay attention and watch which action goes with what.

Cheer-up-when they hold out their arma, press hug, when they look like they are crying press console, when they put their hands on their chest press pep-talk.
Calm-down-when they look as if they are going to punch you press beg, when they put their hands in the air press calm hands and when they put their hand in your face press yell back
Restrain- when they look off-balance and spin around press steady, when they bend and put their arm down (to around their knee) press stop, and when they stick their hand straight out from their side press stern yell
Hope this helps x