Reaper Software Missing Files Error

Hello all
I was trying to organize the music folder on my system the other day.
I deleted some files which were not important for me.
Now when I open reaper for multi track recording and editing of my audio, most of my files end up saying that I need to replace a missing file.
It gives me 2 options to browse for the missing file or ignore it.
Can anyone please tell me what should I do?
I can bet I have not deleted anything important from my system.
Waiting for your replies
Regards and best wishes
Jack
