He. His and Jenny doesn't make sense, him and Jenny doesn't make sense, and we and Jenny doesn't make sense either so it's He and Jenny are going to ride in his car.
According to how the narrative is made, specifically how he tells us what he's done and his situation, it can be intuited that he was struggling in that time and needed to eat, so he had to steal some food but he was planning to return it as soon as possible.
What is the passage?
lol, Parentheses are generally used as an explanation or afterthought into a passage that is grammatically already complete without the stuff in the parentheses. In writing it is u usually marked with curved brackets.
Example: He finally answered (after taking five minutes to think) that he did not understand the question.
I hope that this helps....