first standard poodle grooming appointment in two weeks and im terrified of either getting a bad cut or scaring him off grooming for life, what do i actually need to tell the groomer

Background. Pickle is a 7 month old standard poodle, my first poodle ever, and i had no idea what i was signing up for coat-wise. I have been brushing him daily since 12 weeks (mostly) and i thought i was on top of it. Last week i found a matt the size of a quarter behind his ear that i had to cut out and i nearly cried. He had his puppy bath-and-tidy at the vet at 4 months but next saturday is his first appointment at a real grooming salon and i am realizing i have no idea what to ask for.

The salon sent me a form that asks for "desired length in inches" for body, legs, head, and ears, plus "face style" with options i dont understand (clean face, beard, donut, teddy, lamb). I have watched maybe a dozen youtube videos and now i am more confused than when i started because every groomer has different terminology for the same cut and every poodle person on instagram has opinions. He has not been bathed in a tub anywhere except home and he has never had a dryer on him. The form also asks if he is "matt-free" and i need to be honest that he is mostly matt-free but i found three small ones near his armpits this morning that i cant get out.

What i actually need help with. What do i ask for that wont end up being a shaved-down disaster if the groomer mishears me, what do i tell them about his temperament so this is not traumatic for him (he is friendly with strangers, has never been alone in a building without me, is fine with handling of paws and ears), and how do i talk about the three matts honestly without them charging me triple or shaving him to the skin. Also is it normal to be allowed to drop off and pick up or do they want you to stay. Do i tip and how much. Do i bring his food in case he gets anxious. What length should i actually ask for in inches for a first cut at this age.

Any help from people who have done this with a young standard would be massively appreciated. I want this to go well for him more than i want him to look any particular way