From what I've read in various online sources, it seems to vary a LOT between different providers, patients, locations, etc. Even those who live in the same general location seem to have had dramatically different experiences. But, here is what I remember my process being like:

• Made an appointment with a psychiatrist (THIS WAS THE HARDEST PART BY FAR AND I HATED IT - It took me almost an entire year from start to finish to find psychiatrists that were in-network with my insurance, had open availability that wasn't months and months out, I could get ahold of, specialized in my general areas of need (ADHD + other conditions), etc. Part of the problem was I kept giving up when I'd hit these barriers, to be fair)
• Had a consultation appointment with the psychiatrist where she asked me a lot of introductory questions, going over my general upbringing, career, daily life, concerns, symptoms, things that have helped or hurt, etc.
• Completed a few different questionnaires, some for ADHD and some for other things, like anxiety, and also had to share a questionnaire with my partner for him to fill out from his perspective on me
• Had a follow-up appointment with the psychiatrist plus another more senior psych, where we went through all of my results together and discussed my diagnoses, potential treatment options, etc.
• Had to visit a lab to get general bloodwork done, and also an electrocardiogram, to make sure there weren't any health concerns to be aware of (or that could explain my symptoms) before trying stimulant medications for the first time
• Got cleared with all of that, had an appointment where we settled on a first medication to try, and then continued to meet with the psych every 2 weeks while we titrated my dosage and medication type.
• Nowadays, I only have an appointment every ~3 months with a psych to check-in and continue my prescriptions and/or update things, etc.

I hope that is helpful! I know it is scary starting the process, but I can't stress enough how helpful it has been in the end for me. I'm really glad I pushed through and finally got help.

If it helps as well to hear what appointments were like, I found that the psychiatrists I have had (changed psychs occasionally due to moves) tended to be less interested in detailed discussions about feelings, emotions, or symptoms than my therapists have been. Not to say they aren't interested, they are and they specifically ask things about them. But, they have seemed more interested in a "do you experience this", "is it the same as before or improved/worsened", etc, and less interested when I would go on detailed explanations of exactly what I was thinking during a particular event or experience, if that makes any sense. For example, it seemed like they preferred "Most days, I feel like my symptoms are significantly improved during midday, but I tend to consistently get spacey and sluggish around 5 pm every day. Increasing water and protein intake hasn't seemed to fix it." rather than, "Well, it's different everyday, but I usually take my first dose around 9 or 10 AM or so. About an hour after that, I feel less "stuck" and am able to actually get up out of bed and do 'normal' things, like brush my teeth or get dressed. Sometimes I don't get anything done after that, but I still feel more 'normal', you know? I tried changing my lunch to include more protein, and......" I realize reading this back that this seems like generic advice to not be long-winded and overly explain things, not just for psychiatrist appointments, but I hope what I'm trying to explain sort of got across lol.

I now realize I've written a significantly longer (and long-winded, hah) comment than I intended to, but I hope it is helpful in some way to you or someone else!