Hi Xantequia, your server should be set with a static IP. Otherwise whenever you restart your server or the DHCP (dynamic address) lease time runs out your server will get a new IP address. And your port forwarding will fail.
The Internal IP on the Port Forwarding section of your router is your private subnets static server IP.
Go onto your server, launch a run box and type ncpa.cpl and press enter. This will get you into your network connections. Right click on your network go to Properties, click on TCP/IPv4, click Properties and make sure your allocate an *free* IP address (if you haven't already). (you can ping it before to see if it exists if not (cmd -> ping chosen IP - eg. ping 192.168.0.50) if no reply you know it's free. (Unless you've set devices with no ping reply policies, but I doubt that is the case...).
If indeed 192.168.0.100 is your routers IP (Default gateway) you should have a setting similar to:

You can obtain DNS server addresses automatically, but these come from your ISP and are slow. So I use:
Quad9 DNS is a free security DNS service. 
Quad8 DNS is Google's open DNS service. Google owned and analysed
but fast.
[ And yes, my LAN is called `Network Not Found`
]
You basically have to Port Forward, as private subnets 10 / 192 are special none-routable subnets. Meaning they can't route public internet packs without the router forwarding the packets. The router will have an external (publicly routable) IP.
I would steer clear of 172 addresses myself as they are no longer "true" private subnet addresses. As since 2012 ARIN (IP allocation authority) has allocated ranges of the172 address space to content providers and therefore can cause issues when used on certain ranges.
Incoming ports are important to open up on your firewall too. firewall.cpl from run box (assuming you are using the built in firewall... which less face it is good enough).
Outgoing ports are usually open by default, as the connection attempt is made from within the trust zone. I.e. you trust yourself. I mean, why wouldn't you?
Blocking Outgoing ports only helps limit what damage can be done after a system is already compromised. Generally speaking people who compromise networks don't adhere to good practices, and they'll probably just hook up on ports 80 and 443 (HTTP and HTTPS) so again... paying for an firewall that blocks outgoing ports (Norton 365 I'm looking at you
) is just a bit of a con.
I'm going a little off on a tangent
... best of luck 