You don’t want to go to 0.0.0.0. That particular IP of a server means “any server”, which means the virtual machine listens to all IPs that belong to a computer (useful as a shortcut meaning if application doesn’t want to specify an IP it listens from), but you cannot access your virtual machine without VirtualBox bridge, which sets localhost port 4000 to redirect to port 3000 of your virtual machine.
You should use localhost:4000 instead of 0.0.0.0:3000