Mental health claim

I am close to walking into the VA to be seen for my mental health issues I’ve been dealing with was I was told I can just walk in without an appointment my question is will they just ask me a bunch of questions I have severe depressions and anxiety and was wondering if they will give me a diagnosis or will they send me to a C&P exam ? Ideally I’d like to get a diagnosis for either depression anxiety or combat related ptsd.