Maybe begin with journaling first?
It helps with communicating how you're feeling effectively and warms you up to being open about it before speaking to somebody about it.

You can always get multiple opinions from people, everyone will have a different perspective; therapists are individuals despite operating within the same general guidelines for client treatment and diagnosis. The whole point of therapy is really about you working through your own thoughts with a professional (hopefully) there to offer some practical tools to improve your habits. Opening up completely while directing the conversation to your preferred topics is more likely to offer tangible results. The work is really on you, not just in therapy but every day, making choices towards improvement... Also, understand that modern therapy is quite limited due to our lack of knowledge of how the mind works. We're not really even sure how prescription drugs work.

You're therapist will help you feel comfortable and figure out what to start with. They'll also explain some things to you like doctor patient confidentiality

You want to make the right impression on the therapist?

Just remember they're not supposed to judge you they may or may not know your situation just try to relax and remember they're there to help you 😊

There's no right or wrong way. Just be yourself. The therapist will ask you questions, too