Were do i download my music for making a remix

[Plasma]

im recently got into making music with fl studios 20 however for some odd reason when i go into my itunes folder and i click on a playlist theres no downloaded songs {ive downloaded them so i can play them offline on my computer i tried spotif idk how to download songs on there i think you need premium so were do u guys suggest i get my music at?

 

[Garpocalypse]

Using Itunes you have to convert to MP3's first before importing them into a DAW.  Right click on the track you want and a "convert to MP3" option should be listed.