Some people arrive with a clear picture of what they are dealing with. Others arrive with nothing but a feeling — that something is wrong, that things keep going badly in patterns that do not make sense, that they are not themselves in ways they cannot fully articulate. Both starting points are equally valid here.
The evaluation process is designed to begin wherever you are. You describe what you have noticed — however clearly or unclearly — and the discernment work establishes what is actually present. You are not expected to diagnose yourself before coming in.
You are also not expected to hold a particular belief system, follow a specific spiritual path, or have any prior experience with this kind of work. The only requirement is a genuine desire to understand what is happening and address it. Everything else follows from there.