SSH stands for a secure shell. A shell is either a command line where you type things/commands, or a graphical user interface where you can manipulate things. Think of it as a way to communicate, like Morse code, or even a written language. It’s how you access one device from another device remotely. You do this to have one device tell another to do something.
Tiny cloud is just the name given to an app that will quickly tell you the IP address you need to use to communicate with your Gameshell, along with the login and password. You don’t need to have it running to be able to SSH into your device.
You will need the Gameshell and whatever device you are SSHing from to be on the same network. Sometimes that can be on the same wifi network. You can even directly connect to a computer via USB->Ethernet. Sometimes the wifi host can be the computer/phone/tablet itself. One user even made their Gameshell a file server.
Essentially, consider your Gameshell to be a mini Linux computer, with endless customisable possibilities. If you can write the code, the Gameshell can do it.
After finding a suitable program to communicate with your devices via SSH/SFTP, you enter the IP address as indicated by Tiny Cloud, followed by the username and password. From here on, you will get a command line interface (CLI) that you can type in commands to have the devices communicate with one another. Think of something similar to a DOS Prompt box in windows. Sometimes it will be a graphical user interface (GUI), which will be similar to what you see when seeing files and folders in windows.
You will need to know a few Linux commands. Some are similar to dos, eg, cd is change directory in both. Others are different, such as dir (windows) and ls (Linux). They both list what is in the specified directory. There are plenty of commands to get acquainted with.
A great thing to do if you don’t know what something means is to do a google search, or even just within this forum. I mean this as sincerely as possible, without any condescending implications! Everyone needs to start somewhere. This is how you can actually learn a lot, which will in turn allow you to learn even more, come across new terminology, and increase your skills and knowledge! 