how to install Debian 9 minimal server "network interface question"

i am going through tutorial on installing a debian 9 minimal server and have come to the network interface part of the tutorial.

This is for an instance on Google Cloud Compute.

nano /etc/network/interfaces returns...

# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto eth0
iface eth0 inet dhcp
​

the tutorial asks me to enter the following information (i believe i should be substituting ip address for my own)

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto ens33
iface ens33 inet static
address 192.168.1.100
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.1

​

Questions...

1. Which ip address should i input, the external public static ip (35.197.169.13), or internal static ip (10.152.0.3)?
2. a lot of the information in this file i am not sure about. On google cloud compute, what details should input for netmask, broadcast, and network?

here is a bit of information i got off my console for VPC Network and gateway in my selected region.

australia-southeast1 default (subnet) 10.152.0.0/20 (ip address range), 10.152.0.1 (gateway)​

 

I think you only use public ip when using vps and you do not need to set anything for the interfaces as they are all meant mainly for local network.

 

ah ok. thanks.