I have no clue what to do now I need advice (long post)

At 2, he can know “no hitting” but still not have the impulse control to stop when he’s overwhelmed. I’d focus on triggers like noise, transitions or lots of kids, keep responses really simple (“I won’t let you hit”), and help him calm/change environment. With his speech delay and upcoming therapies, I’d also ask them to help make a consistent plan daycare can follow 🤍

Hi! I’m a graduate of special education and I’m not saying this because I’m saying that your child has needs but I wanted to share some things we are doing in this kind of situation. Expose your child into activities that would tire him out (i.e. running, jumping, etc), have him spend more time in playgrounds (indoor and outdoor is fine). We have to work on his social skills by exposing him to environments where there are a lot of kids. We don’t need to rush him but more so let him see how it is with other kids without pushing him to mingle. I hope this helps!

My son is semi verbal & nonconversational, so I get it.

We bought a plastic bottle to send our son to preschool with because we did not want to risk a metal bottle ever getting tossed or thrown at anybody.

I think I’d do my best to communicate everything you shared here to those who care for him while he’s at daycare. Explain that he may need a change in scenery and some moments in a quiet space to re-regulate himself

We also at home use careful language, we don’t say “don’t throw that” we say “keep that in your hands” stuff like that, stuff that makes direct sense to a 2-3 year olds brain.
And I’ve communicated key phrases we use in our daily life to his teacher so she knows what works outside of school & can find a way to incorporate it into her own methods

I can't offer much advice because it sounds like you are doing everything you can. Only things I would maybe consider are;
1. behaviour plan for school, so things they need to do in certain situations so it is consistent at both home and school but also to help him control the behaviour.
2. Flashcards (my kiddo was speech delayed and this massively helped) to both get him to speak, allow him to communicate and allow you to reinforce when behaviour needs to stop.
3. Reonforce positive behaviour and the behaviour you want to see.
4. Try and focus on the behaviour you want to see not the negative behaviour eg "We walk" instead of "no running" or "we use gentle hands" instead of "we don't hit".

I also want to mention that non verbal doesn't mean he is behind cognitively. It just means he struggles to communicate for any number of reasons.

Also, want to reassure that things will get better......

Don't rush to the conclusion that things won't work out because he had a bad first day. Tomorrow is a new day and an opportunity for him to feel better and do better. Read books to him about the first day of daycare/preschool and ask if that's what his day is like. Point out all of the good social behaviors in the books and the feelings the characters have. Give the school your list of ways you help your son when he's overstimulated. They are just getting to know him too. Try to set him up with some really solid routines for before and after daycare that can carry him through the day without needing a bunch of decisions. He can do this, and so can you. You will get through this transitionary period together and come out stronger for it. 🍀