2.5 y/o first time daycare/hitting issues

ok so my son will be 3 at the end of September.... we had been on a waiting list for daycare in our area for the last 20 months and finally got the call that a space was available for him 2 weeks ago. its just part time. 2 days a week for the socialization. (he also has speech therapy once a week for an isolated speech delay).... we have no friends or family nearby with kids his age and no kids programs with this covid stuff so he really really needs this daycare socialization.... he did great the first 2 days, but today was day 3 and he got his first note home about hitting other kids... he dosent hit us and when he does get in trouble for other things we try to explain to him why it was wrong and not to do it again and it usually works pretty well. he already struggles with communication so i dont want him to resort to expressing his frustrations physically so we dont hit and try to lead by example. apparently that's not working cuz he learned to hit others pretty fast.... the teacher at daycare said they dont want to start doing time outs just yet because he is still adjusting to daycare.... eventually they will have to do time outs and thats fine. but if i cant replicate the problem at home and correct it in the moment and i cant communicate with my child yet about how his day went then how do i address this on our end? this Momma is having some anxiety tonight.... i know.... he is 2 and learning to interact with others isnt easy.... but he's always been such a sweet and easy kiddo. this is new territory for me.