$ lsblk
Using lsblk command you can check the device name and its mount points. Here you can see sda mounted to /media folder.
Then make sure you are inside the folder where you want to copy the files from.
cd into /run/media/srhills/BU_Drive/
[srhills☮minipcpn62]-(~/archlinux-nemesis)-[git://main ✔]- └> cd /run/media/srhills/BU_Drive/
┌[srhills☮minipcpn62]-(/run/media/srhills/BU_Drive) └> sudo cp .tmux.conf ~/archlinux-nemesis
[sudo] password for srhills: ┌[srhills☮minipcpn62]-(/run/media/srhills/BU_Drive) └>