That it's a big jump from nursery, our kids were in the school nursery attached to the school not even a private one, but don't anticipate you get to speak with someone when you collect your child. They will literally just send them out the door unless they peed themselves or something 😆.
If you are precious about monitoring what they eat send a packed lunch, you'll never know how much or what they ate at lunch otherwise.
Be prepared to replace lost uniform, a lot. We spend hundreds each year on uniform. My middle child managed to lose 2 brand new jumpers in the first 2 days back last year they reappeared a month later (they were labelled). I was furious, school really don't care, they will just shrug, but then you realise there are 240 kids in the school they don't have time to keep track of 240 sets of uniform.
So yes label everything, even shoes. My daughter came home with someone else's shoe on, they were the same but a different size, I wouldn't have noticed if I hadn't put a name sticker in.
Be prepared to be sending money in constantly.
Join the class whatsapp group they will help you keep track of the 20,000 requests and 12 different apps that you are meant to keep on top of each week.
And finally try not to be "that parent" the teacher has around 29 other kids to look after, although your kid is the centre of your universe at school they are just another kid in the class, don't be the ott precious parent waiting to speak to the teacher every single day.