Welcome to Android Central! How did you delete the music file from Internal Storage -- using a file manager app, or Windows Explorer while the phone was connected via USB? Try going to Settings>Apps, select your Music app, then Storage, then Clear Cache/Clear Data. Now open the Music app again and wait a few seconds for the database to rebuild. Do you still see the duplicates?
Music files can pretty much be saved anywhere on the phone, and they'll show up in the Music app's list, because the system scans all directories regularly for new media to add to the database. The exception would be directories that contain a file called ".nomedia", which instructs the system to ignore that directory when scanning. For locally saved music files, I recommend saving to a directory called /Music, and maintaining the standard folder hierarchy of Artist>Album>Song. (This is more for your own benefit when it comes to file organization, because most music apps organize songs based on embedded ID3 tag information within each music file.)
04-03-2018 11:25 AM