My iPad and iPhone are no longer synced ever since downloading the new iOS what to do?

On your iPhone go to Settings/Messages, tap Text Message Forwarding, and turn on the switch for your iPad. This allows your iPad to both see your texts and to send and receive through your iPhone.

Also, go to Settings/{your name}/iCloud - Messages and turn on the switch if you want to sync them to iCloud. Do this on both the iPad and iPhone.

Note that the iPhone and iPad must be logged in to the same Apple ID in Settings/{your name}/iCloud.

Synced in what way? iOS devices never sync with each other; they sync will an external entity. For many functions (calendars, contacts, notes, texts, photos, etc) they will sync with iCloud if you enable that function in Settings/{your name}/iCloud. But you must turn on the sync switches for everything you want to sync.

Mail never syncs that way; instead, each device syncs separately with the mail server.

Where are you seeing sync problems?

Synced to what? What is it that you are trying to do and what happens when you try? You have to explain what you are trying to sync for someone to try and help with the problem.

Great, glad to hear it!