deleted startup disk

so i think i accidentally deleted my startup disk file and some other important stuff while trying to clear system storage. i have tried holding command + r in startup to go into recovery mode but this has not worked either so i may have deleted the file from that too.

my macbook air screen is black with a loading symbol in the middle that flashes on and off along with the cursor.

does anyone know how to fix this or what to do to reset it? i know this was a silly mistake but i would appreciate any help.