Q: ive backed up my iphone using the wifi but phone still says it cannot backup and i have to delete some data

This article provides some suggestions for reducing your iCloud storage: http://support.apple.com/kb/ht4847.  In addition to what is mentioned there, if you have lots of photos and videos in your text messages, they can significanly increase the size of your backup and the storage necessary to save it.  Deleting these from your text messages will reduce your backup size.