Metal closet door about two feet wide

hii I have this closet door I need to buy replacement parts for it I about two feet wide metal and the bottom only has one circle thing at bottom and top I think you are calling it the pivot bracket. Should there only be one per rail ? Is it cheaper to buy these parts in a set or individual , also do you send paper instructions on how to install ? I think the web site you guys have is awso even and very easy to navigate.