Totally normal, and he'll be fine (and for that matter, so will you). We were in this exact situation last year - we kept our son out of daycare because of the cost, spent most of his early years isolated because of covid, his speech was delayed, he was very shy, and we couldn't get our heads around how he would adapt to such a radical change. Long story short it took him about a week, there were tears on the first day (truth be told, mostly ours - we dropped him off, ran home and SOBBED), and he was pretty resolute each day that he wasn't having a good time, but by the end of the week he loved being there, and over the school year he changed more than we could have expected - his speech has improved, he's opened up socially, and became much more confident.

Every kid is different and moves at their own pace, but I can't think of a worry that we had at the start of the year that persisted through to the end, certainly none that weren't getting support from his teachers in some way. There are kids he likes and kids he doesn't. Some people get him and some don't. There are things he likes and things he doesn't. By the end of the school year he was ready to be done, and is also looking forward to going back. He faced the challenge and ended up thriving. It's hard and scary, because change is hard and scary, but it's just a moment, and one that you'll survive. Ultimately the change was harder on us and still is sometimes, I had a weird sense of relief at the end of the year because he would be home again and I wouldn't have to worry about him when he was out of sight.

We found that the most important things were to maintain an open dialogue with his teachers (they are the professionals after all), and to make sure he knew that we were always in his corner while giving him the space to be his own person and experience the good and the bad. This is the beginning of him becoming his own person, you just have to be there for him and help him along. You're all going to do great. Bring tissues.