Recover conversations and everything

Hello, I don't have whatsapp security copy on the cloud.
I only have the folder in the internal memory : Whatsapp.
I have copy this folder to the new device where I have the new whatsapp account associated to the same mobile number.
I have not recovered the conversations.
What can I do ?
1. I have closed the account in the old device. Now is associated the number in the new device. Can I close the account in the new device and reopen to see if the databases in the folder whatsapp are recognised ?

Best Regards