The very first session will be an Evaluation. You will be evaluating your counselor while they are evaluating you. You will be considering if it might be a good fit and you want to come back. They will be trying to figure out what is going on and if they can help. They will ask you many questions, including what prompted you to call, then your counselor will present if/how they can help you. Afterwards, you will decide if you wish to go forward. If you do, our standard practice would be to complete an Assessment.
The next 2-3 meetings would be a more in-depth Assessment of the problem(s) and how they came to be. At the end, your counselor will present their findings and, together, you would develop goals along with a plan-of-action to move forward. The assessment would provide recommendations that might (but do not usually) include a full psychiatric, psychological or medical examination. At the end of the Assessment, both you and your counselor would have the opportunity to discuss/reframe/develop our findings into a plan-of-action, including how often you meet (e.g., weekly, bi-weekly, monthly, etc.) from then on.
Certainly, this is our normal practice. If you come to us in a crisis, the flow may be different at first but we would eventually want to slow down and get back to the in-depth Assessment when things calm down.