simple way of organising your apps in order of importance onto various screens on the device through the iTunes store
If by 'iTunes store' you mean via your computer's iTunes then that was removed in iTunes 12.7, if you want to be able to do it via iTunes you will need to install version 12.6.3 or go back to an older version. You can still organise apps directly on a device.
There also used to be a way of downloading a manual
iBooks have also been removed from iTunes 12.7, but you can still get books directly in the iBooks app on your phone (and iBooks app if you have a Mac) or you can browse an online version on your computer : Apple - Support - Manuals