To repeat my reply to you, of your duplicate question, made earlier today...
You should each have your own AppleID - as the account relates to a person, not a device.
For consumer devices, iPad and iPhone follows a “single-user” paradigm - meaning that logged-in services generally relate to a single-user. Whilst different services can be “logged-in” with different AppleIDs, you need to be mindful of the implications and any unintended/unexpected consequences.
Consider also that App purchases and Service Subscriptions are tied to a User, not the device. As such, any Apps that you purchase can be used on all the devices that are associated with your AppleID. Using different AppleIDs for each device can rapidly become expensive - and both keeping track and properly maintaining all the different AppleID accounts can become complex.
Whilst you could decide to create another AppleID for your notionally “shared” iPad, you are going to run into all kinds of issues. You would be best advised to decide “who” is the owner of the iPad, and complete initial set-up with that AppleID. Knowing who the device “belongs to” becomes important if you ever need to re-activate the iPad - or if an Activation Lock should ever occur.
The best way to manage your family devices is to ensure that you clearly define which devices belong to who - and use the appropriate AppleID of the owner to initially activate the device and log-in to iCloud Services.
Next, consider use of the Apple Family Sharing feature. Decide on who will “lead” the family group and become responsible for App and subscription payments. Add the other AppleID to the family group - and configure which content you wish to share.
Family Sharing
https://support.apple.com/en-gb/HT201088
https://support.apple.com/en-au/HT201085
As for other services and social media accounts, so as to maintain seperation, log-in using your own account for each service. For Apple services, such as Messages and FaceTime, you should use your own AppleID.
Following this strategy allows you to select the content (media, pictures etc.) to share between you via Family Sharing - whilst keeping “what’s yours” on your own devices.
For your shared iPad, whilst the “owner” should log-in to iCloud using their own AppleID, you might choose to use a different AppleID account for other services. Just be mindful of the need to understand the potential pitfalls of this approach - as data “leakage” and “mixing” can occur.
I hope this brief explanation is helpful in guiding you to an acceptable solution.