Need guidance on how to erase certain data from USB stick

I am using a MacBook Pro running macOS Monterey V12.7.6 I've downloaded ton of music from my harddrive from my Mac on to the Lexar USB stick and for some reasons a lot of duplicates appear when I pop the usb stick in the car to listen to the tunes. I try to fix it by erasing the item(s). I pop the usb stick here in my Mac finder appears. I highlighted the item(s) I want deleted and press move to trash. Eject usb stick properly and when I plug in car items still appear and play. What am I doing wrong?