Tor network on Virtual Box

Hello I want to create a similar network philosophy as tor, with Enter Node, Middle Node(Router), Exit Node

I created 3 ubuntu servers linux distros on vbox

Because exit node has outside connection he has NAT adapter

He also has internal network in order to communicate with the middle node(router)

The middle node has the same internal network

PROBLEMS:

1. I don't see any network interface with IP on the middle node(he has only internal network adapter)
2. I don't know if the internal network of both nodes should have the same MAC address
3. I don't understand why the internal network doesn't have IP at all
4. How to forward ANY traffic from the middle node to the exit node?
5. I'm trying to ping anything from middle node and I can't reach anything (public ip of exit node, the NAT of exit node, idk what to do)

EXIT NODE:

https://imgur.com/a/7FLQIqF

MIDDLE NODE:

https://imgur.com/a/E6Ej9Hw

The mac address of the internal network (same name: my_inet1)

is 080000000000 (i changed it manually, idk why)