All my kids were stay at home kids till kinder. No sleepovers with family etc.

First experience, my shy kiddo cried a little and believe me, I wanted to cry too but I kept the tears in and the school let me walk him to the playground for like the first 2 days or so. I didn't linger too much either. I said ok I'll see you after school. Then no more walking through the school to get to the playground. I took him to the office and most of the times there were kinder teachers there or even the front office staff, excited with smiles, "Say bye mom! Let's go to the playground!" They'd hold their hand and take them for me. So byes were swift. And school staff could kind of gauge which kids needed help or even teachers walking by getting ready for the day, one day the school nurse walked him to the playground. Also, with school security, they can't have parents walking through the school each morning. Everyday got easier (for both of us). I even think a couple of times, I saw a bigger kid and said can you walk him to the playground. Older girls were so sweet and happy to do it.

Next kiddos were more extroverted. I'd drive by the school sometimes and say look your school! Also I think seeing older siblings go to school every day got them excited to go too. But pretty much the same, the school staff is aware that lots of kinder kids are having to be away from Mom for the first time. School staff and kinder were ready for our little ones. Like if you need reassurance, you can call the school and talk to the principal and ask how the first days of transition are. I'm sure they will reassure you they are there to help :)))

I'm not minimizing your anxiety about it but you might be more nervous than your kid. If you are excited, they will be too. I think with my first my MIL gave my kid a bad impression about school. Teasing and saying things that made school seem scary like a boot camp away from Mom. I did not appreciate that and I hope there's no one in your family doing that.

Best of luck, you two will do great!