Here's what therapy notes are and how therapy notes work: Psychotherapy Notes and HIPAA | Psych Central - Part 11

The therapist can take notes for themselves, like you would writing about therapy in a journal for yourself and they don't have to shows those to you. If you are self-pay and no insurance notes/diagnoses, etc. are kept/needed then you might not get anything if you ask a T for their "notes". Formal medical notes in a hospital or treatment group situation, etc. may/may not be very "accurate" to our own point of view; most of them are for the insurance company's benefit so they will pay.