Thing about a topic that interests you within the field. Or, consider something that you have seen, read or heard. At this point you need to start focusing on a broad question and/or questions related to your general topic.
Once you have your general questions, try to find terminology related to your topic through a literature search. Look at bibliographies from general communication books (like your textbook) and start digging.
Before you contact community members and government officials, do your homework. You will be able to ask better questions, which will lead to a better responses.