Setting up my new iPad
How do I complete the setup of my new iPad when I keep getting “If you restore this iPad from an iPhone backup, settings will not be restored”?
It should be safe to continue. It's just giving you that message because the iPad and iPhone are different devices so it's not going to be able to transfer everything over. Most stuff should, but you may need to go into Settings after you restore it and set them manually.
Your other option is just to set up the iPad from scratch (my preference, personally), and if you have anything to sync over you can do it via USB to the computer or you can use iCloud to sync wirelessly.