VPN tunneling, routing and sniffing

I did not understand some things regarding the VPN.

How is the VPN tunnel established? My computer and the end VPN server need to exchange some info to establish a tunnel? (some kind of handshake or do I miss something?)

How VPN packet finds a way to the destination machine if the entire ip-datagram is encrypted? I understand that the packet is is encapsulated within another packet, but the source and destination IP must be the same or?

E.g. I am in a restaurant, and I connect to my corporate network via VPN.

so is: MyComp -> restaurantRouter -> internet -> routerCorp-> specific server corp

If someone between 2 routers sniffs the packets, they can see that the packet goes from restaurantRouter to routerCorp? right? Or they cannot see the full path?

If someone between MyComp and restaurantRouter sniffs the packets, what they can see? Can they see source and destination ip?

The restaurantRouter or their ISP knows that I am sending packets to routerCorp?

Does the restaurantRouter or the ISP knows the content of the packets or are they already encrypted when they reach the restaurantRouter ?

Do the packets travel same path or this has nothing to do with the tunneling?

EDIT:
By the last question I meant:
Does the VPN packets travel the same hops (different routers) between restaurantRouter and routerCorp or is just a normal packet switching travel? (because the word tunneling confuses me, and I am not sure if this means also that the packets travels the same route all the time from beginning till the end of the VPN session)

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