You cannot sync the two directly. You have to get the content thats on your phone, onto your computer. Once there you import intoi itunes, then sync to ipad. This is not all easy, depending on the type of content, how it was obtained or purchased. Simply backing up, does not transfer any content from one device to the other, you have to sync the content.
How to transfer or sync content to your computer
How to sync iphone to computer
Syncing multiple devices with one computer
IOS: Syncing with iTunes
Apple - Support - iPad - Syncing
ITunes: Syncing media content to your iOS devices
If all the music was purchase through itunes, then you have fairly simple options. Either download directly to your ipad, or download to computer and sync to ipad.
For photos, you can also add them to 'photo stream' and then will show up on ipad when you turn on 'photo stream' on ipad. But you have a 1000 photo/30 day limit to get them off photo stream and organized.