Working at McDonalds.. CONFUSED .. PLEASE HELP?

ok i just got my first job working at McDonalds. My step mom knew the manager so i just basically got the job. I went for an interview and the manager told me to come in Monday for training. She told me to wear all black. i am so confused because the manager had on all black. she never said a specific kind of shirt. I called the place and an employee told me to wear a black shirt. they would prefer it to have a collar. But i don't have that. Is this just for training until i get my uniform. Because people are saying its different at every store. will i eventually get a shirt and all that other stuff?? and when?