Does anybody know how to back up a iPhone 6 Plus to help my storage on my phone please and thank you it would real help me and everything thank y'all and have a blessed day or night.
Regarding back up of your device try this steps:
Manage installed programs by removing/deleting programs - files you don't want or need from Setting/Geeral/Storage & iCloud Storage:
1. storage (internal programs from iPhone)
2. ICloud.
Afterwards it is possible to back up your iPone with I Tunes.
Two popular ways to create a backup with your iPhone are via iTunes backup and iCloud backup. Instructions for both can be found via the following link.