Hey, I am a learner, How many of those people would you confide in if you were having a crisis of some sort? MEANS How many of those people would you confide in if you were having some sort of crisis? Take a look at this conversation. Rohan : Hey, did you hear that news? Rohit : Yeah, I have heard of that, it is about some sort of accident, right? Now I changed this to singular accident. It is about an accident of some sort. Rohit knows it is about an accident, but does not know what kind of accident. For example, is it a cycling accident? ... or a skiing accident? let's get to the next point : How many of those people would you confide in if you were having a certain crisis ? Here certain means some or particular. Specific... Suppose you got a family crisis on your hands – your 16-year-old sister is pregnant or you have some dirty secrets that you can't share them with anyone. Well. As I told you before, I am a English leaner. Let us wait for the native to throw light on the problem.

"Of some sort" is not specific, so it could be any type of crisis. "a certain crisis" is talking about a specific type of crisis. This could be of many types, such as a financial crisis, personal crisis, etc. To summarize the 1st question is asking how many people you would confide in during any crisis and the 2nd question is asking how many in a specific type of crisis.