It's a completely normal thing on performance cars, especially when you live in a humid climate. If you hate it that much, move somewhere with a dry climate, or change to something like the StopTech Z16 ceramic brake pads, as it's the metallic pad causing the issue.I have a 2020 with 2300 miles on it now, I bought it a month and a half ago with 1400 miles on it and I have the same exact issue as you! It makes the same noises as you described when I first drive it for the first few miles each day or if it's rained or gotten wet. It makes a car horn sound as you are easing to a stop and it's annoying and embarrassing on a fairly new car.
I have a pond in the back of my house that tends to make the carport where my Supra is parked substantially more humid. When I first start driving every day, my brakes sound like a damn train horn. It's quite sonorous.