I have been using Octoprint for around a month now with no issues at all except for disconnects during longer prints (1-2hr)
Recently I cannot access the server using my RPi's IP address. (http://192.168.0.12/)
I however have NoIp set us with a domain and I can access it through that just fine.
I have tried accessing this IP through many devices on my network with no luck.
I already setup port forwarding and set up a static IP for my Pi. Restarted the server multiple times, still no luck access it. It just says page cannot be reached.
I can't SSH into the Pi either. Cannot make connection.
You setup port-forwarding so that hackers can access your Pi within minutes and to own your OctoPrint installation (because No-IP told you that this is normal and you believed them)
Things we don't know:
Whether you are using wi-fi, an Ethernet connection on your Pi or both
What kind of workstation you have (OSX, Windows, something else)
Whether or not you have changed the hostname of your Pi
Whether or not you added access control during the Setup Wizard
Whether or not you enabled SSH on the Pi
If you installed the OctoPi image or did you install OctoPrint using the manual instructions
Begin with the basics: what is the actual hostname of the Pi? By default for the OctoPi-related installation, it's octopi but you can append .local to that for your purposes.
Can you ping octopi.local then? If so, what do you get when you try ssh pi@octopi.local? You'll either get a prompt ("raspberry" as the default password) or you'll get a message indicating that the connection failed. Copy that here.
It's a really bad idea to expose your Raspberrry Pi's OctoPrint instance to the Internet using port-forwarding. It takes about fifteen minutes average time for yet another "script-kiddie" to come around and start hacking it. This isn't an exaggeration.