how do i download music onto my sd card?

i am trying to download music from my itunes account onto my micro sd card for use with my android phone. currently it says that i am unable to do this due to my computer not being authorized..however my computer is authorized. how can i fix this so i can download the music from the icloud onto the sandisk card so i can use my android as a music device untill i can get afford better options? Also if anyone can help with changing the email account information for the security questions id greatly appreciate it. and what do i do if i dont recognize a security question that is on my account? i no longer have a phone to do make calls with. PLEASE HELP FOR ONCE ITUNES!