Hello Gerby76,
From what I gather from your post, you have an iPad updated to iOS 8 and an iPhone running iOS 7.1.2 and would like to access iCloud Drive. iCloud Drive requires iOS 8, which would explain why you can't access it using your iPhone:
System requirements for iCloud - Apple Support
| iCloud feature | Minimum requirements |
| iOS | OS X | Windows |
| iCloud Drive | iOS 8 | OS X Yosemite | - Windows 7 or
Windows 8 - iCloud for Windows 4.0
|
Thank you for contributing to Apple Support Communities.
Take care,
BobbyD