Motorola KRZR K1m

ok so maybe its a dumb question but the manual is just as dumb as me! haha... i have a krzr k1m through us cellular. i was wondering the steps on how to get music on my phone. do i have to buy or download a certain program? i have wmp. also.. what kinda memory card is good for the phone? anywhere i could get it cheap?
to anyone who responds thanks for the advice!!!! 😁