Using the same IP address all the time makes it easier. It usually doesn't change, but whenever a system is used as a server, it's better to use a static IP address. You need to open ports and forward them to the system that will be the server.
You forwarded the required ports to your server's IP address and it doesn't work? Is your firewall blocking them?
Edit: Can you explain this statement: "So, I set up my static IP. (portforward.com) But I didn't have a second DNS when I typed ipconfig /all. So I made up the second one."? If you have a static Internet IP address, then why would you use that site? Is the confusion between the LAN static IP address and an Internet static IP address?