Well, I cannot find it as a phrasal verb. So it must be an idiom?
Its terrible what happened to Sarah’s father, but ‘life goes on’, means, after something tragic happening, life is still going to be okay or alright. Things are going to be okay.
This is definitely an idiom.
You can count on Tommy, he always ‘goes that extra mile’ means, a person who will do more than is expected of them.