It is not the Passcode that is causing the problems. When signing out of your husband Apple ID, all the apps and photos will remain on the device. When signing in with your Apple ID, your photos will download to the iPad if "Sync this iPad" is turned on in settings which it most likely is and it is possible that his photos are now added to your iCloud Photos. You apps will not automatically download and his apps that are on the iPad still will require his Apple ID/Password to update. This is just not the ideal way to accomplish what you want.
The correct way to set up the iPad with your Apple ID with the same settings as your iPhone is:
- First make sure your iPhone is backed up by tapping "Back Up Now" in settings and wait for it to complete.
How to back up with iCloud - Apple Support
- Factory Reset the iPad. Not that the instructions are for iPad or iPhone, but the pictures just show iPhone.
How to factory reset your iPhone, iPad, or iPod touch - Apple Support
- Set up the iPad using your Apple ID. You can use the Quick Start method to transfer info from your iPhone.
Set up your iPhone or iPad - Apple Support
