When you're writing the story how often do you have to skip a line? How do you know when the speech is supposed to be part of a paragraph? I'm having trouble but I can't find anything that will help me.
I think the OP meant she's having trouble with the actual dialog. The second character's responses, etc. The only answer to that is to listen to people talk. Pick up how they respond to each other. Also, READ. learn how other authors do it.
I believe, and please correct me if I am wrong, that the actions of one person and the dialogue of another, can not be in the same paragraph. though this might not be the case for novels written with 1st person narration (or is it?)
As an example:
John grabbed his bag and ran for the door. "Where do you think you're going?" his mother asked.
should be:
John grabbed his bag and ran for the door.
"Where do you think you're going?" his mother asked.