Why are  you still struggling with your very first question on this forum? https://proconnect.intuit.com/community/proseries-tax-discussions/discussion/what-simple-devices-i-n...

You should have a network license and enlist some professional help for the network. 

https://www.instructables.com/Peer-to-Peer-Network-Sharing/ if you really want to do it DYI

I believe your current set up is a real disaster in the making. "I am not confident when the user makes any mistake in public " says it all