Samsung Android S9 ATT Business Phones and tablet set up

Set up 2 Samsung Galaxy S9 Android phones and Tablet for business I have two Samsung Galaxy S9 Android phones and a Samsung Tablet, and ATT business phone service, out of the box and have not been configured/set up yet. I presume all my needs and functions can be set up through apps and the phones’ and service functions (which you can research, present, and configure). I want one business number for my clients to initially contact my business. Most clients communicate with my business by text, phone, or emails (in that order). I need to always promptly respond to all texts and emails and answer all calls (I never want a call missed or a text not promptly responded to), so I will have two phones with two people (or more in the future) to always answer if the other is busy or unavailable. I also need to be able to connect callers/clients to other numbers (my agents/brokers), besides the 2 phones mentioned. Texts and calls come in through regular mobile services and through messenger, WhatsApp, Signal, etc. Need to be able to receive and reply to all such text and voice services. Need branded signature line/header/VCard with my business’ logo and contact info for texts, emails (and calls?), want such logo and contact info to be able to be copied and shared, but would like other security/privacy features that prevents copying and screenshots of other text communications. Want to be able to use/synch the main phone and tablet so I can use text/messenger and other functions on tablet. Also, can it be set up to admin/use other internet marketing platforms from both phones and tablet, such as Facebook, Instagram, Twitter, Google Adworks, etc.