For some questions you should refer the student to a more appropriate source, such as a counseling center. Likewise, legal advice and many other should be referred elsewhere. There are some things you just shouldn't know about your students.
However, for other things, there should be no issue, especially if you have a habit of sitting around with groups of students. Being human to your students is a good thing. You can, of course, express sympathy in situations in which the student is having external problems, and you can give academic advice since that is your field.
Politics is a bit dicey. If you disagree strongly with a student and your subject isn't Government or similar, then you are in danger of the student disrespecting you generally even when you try to teach them, say mathematics. It can make them less able to learn from you.
Likewise, relationship advice can be fraught if you aren't trained as a counselor. There are some things you can say (like "seek counseling"), but you are likely hearing only one side of the story if the student has problems and your advice may well get misinterpreted and applied in ways you don't intend.
Step carefully between being a human being and possibly getting into the middle of things for which you have no training.