How to create local music source on SDCard File System

[spiros79]

Dealing with some issues with my available large external drive , I 'd  love some instructions on how to make use of the SD card as a source . I reinstalled the legacy 32 bit  Moode in my pi zero w using an available 128 Gb kingston SD . On my win11 machine I could only see the boot partition . On my Linux machine  I detected the SDCARD  directory but it says that I don't own it , so I can't  copy anything there . I'm totaly  new to linux , trying to learn step by step . So any suggestion on how I can make the sdcard file accessible would be appreciated . I suppose I must use the terminal and  change permissions allowing everyone while the card is in the raspberry ?  Can I do this in my Linux Mint machine ?

Thanks