This is just the subtitle file!
I made the English subtitle for the preview that was aired on NTV yesterday, and then timed to the following file: https://nyaa.si/view/1596071
I only used Arial in the subtitle, so you don't need to download any other font. I hope the preview is fun to watch, and make sure to watch the full movie, whenever it comes out in your territory!
Suzume's official website: https://suzume-tojimari-movie.jp/