I don't know how to jailbreak but my brother did. But when he got the Cydia app the app picture was white and when I tapped on the app it barely showed for maybe 3-5 seconds. So I want to know what happened. Please help
Ask your brother to re-jailbreak it. It sounds to me like something went wrong while he was jailbreaking it and Cydia was corrupted.
Also, when you get Cydia working, get the following things:
Winterboard
Five Icon Dock
Five Icon Switcher
Installous (You have to add the hackulo sourse cydia dot hackulo dot us/)