I barely talked to anyone on first day of high school and now I m scared I wont have any friends

Do I know I have social capability from being at the psychiatric day hospital for a few months but now that I went to high school all that capability seems to be fine on the first day I only barely talked to two girls but had no idea what could I add to conversation they were having.

The biggest problem I had is that I barely meet people I can talk without worrying about that I wont know what to say and almost only meet those people in places like psych ward and psychiatric daily hospital so now I m scared I wont meet anyone I could talk to for the four years of being there (the school only has 150 people and the first classes only consist of around 25-35 people)

I m scared I simply wont meet anyone that I can talk with without akward moments of not knowing what to say next