Trying to sync iphone to ipad

Not sure what you mean. You don't sync your iPhone to your iPad. You sync them both to your computer.

Please explain

You cannot sync an iPhone to an iPad. While you can share or sync some content, there are only selected items that can be done. Your statement is lacking in detail so it is difficult to understand exactly what you are trying to do. It seems as though you want to put your messages and pictures on both devices via Wi-Fi? With Continuity, you can share messages, and pictures could be shared via Photo Stream.