1. this cannot be directly translated in English. But more translating its meaning. The closest would be "I felt very agitated for that lady, and ventured out foolhardily.....
2. similarly it is not to be directly translated. It means "The man stared at me, it is such a big park, so many scenes to see, but you only pay attention to the girl, you are so low."
3. "无聊" conveys a message that you have too much time to kill, so you have to do something meaningless, worthless, low value. In other words, this adjective is normally used to describe those people who have nothing to do (at that moment). "人家姑娘“ just means girl