You would need to open the app once and run through setup until it asks permissions. The folder appears right after granting permissions.
Yes.
You can clear data by going to the apps information page in settings. Clearing data does pretty much the same thing as uninstall/reinstall. WhatsApp will always look for the latest backup on the device (or Google Drive). You cannot choose an older backup.
You would need the complete folder structure from the previous time and just paste that one into the com.whatsapp folder instead of the latest one.
8. If I only have a single file from WhatsApp/Databases folder msgstore-2020-01-25.1.db.crypt12 , if I only put this file msgstore-2020-01-25.1.db.crypt12 into [internal storage/Android/media/com.whatsapp/WhatsApp/Databases] and restart the Whatsapp app will it load the history before 25 Jan 2020?
9. "WhatsApp will always look for the latest backup on the device (or Google Drive). You cannot choose an older backup." does it mean if i want to load a older backup the only way is to copy the older (that date that I saved) folder WhatsApp and put into [internal storage/Android/media/com.whatsapp/]
10. Does whatsapp during setup restore from internal storage or google drive first? How to specify whatapps to restore from internal storage or google drive during setup?
11. After older backup is loaded, how to prevent new messages from coming in, I only wish to read old messages for a while then later restore to newest backup? If a new message is received during the older backup is loaded, how to move it to the latest backup?
12. How to download the google drive whatsapp backup to save it into PC? I do not find any way to do it.
Thanks.