I agree with other answers and recommend that you should at first try to use common sense and ask for validation to ensure you are not going down the wrong path. A good way to do that is using a phrasing like the following "I am not really familiar with this industry, however I believe the major cost buckets would be x,y,z. Is my understanding correctly or am I missing something?"
As stated, just asking what major cost components are would reflect poorly as dividing costs just in fixed and variable which would seem too superficial/"frameworky".
Hope it helps,