Its best to use the same Apple ID on hyour phone and ipad, that way you can choose what items to share between them, like messages, or apps and games.
It will not affect your Verizon plan at all. or your husbands phone either.
Apple ID's are independent to your cellular plan.
You would want to have the same Apple ID for your devices, but one that is different from the one your husband uses on his devices. So your iPad and iPhone should use your Apple ID for both ( not your husband's)
This again has nothing to do with how your cellular plan is set up.
For messages you absolutely want different Apple IDs for you and your Husband.
You may choose to share an Apple ID for purchases in iTunes and App Stores so you are able to share that content, while keeping Messages and Facetime separate.
You can go to:
Settings->iTunes & App Store
And Manage your Apple Id for each service independently