I've conducted some of research among the Generation Z cohort (teenagers), please refer to my ResearchGate profile for examples of the articles.
However, you need to decide what the focus of your research topic/focus/problem is, which is usually depicted via constructs/scales (i..e dependent variables). The actual Facebook usage questions are the independent variables, from which you can also conduct cross analysis versus your dependent variables for further insight.
I've attached an example of a Facebook questionnaire to illustrate, which includes examples of Facebook usage questions and constructs/scales.