Get Putty
Real power users of any com,puter system use a console to enter commands. using a graphical user interface may be sufficient for most end users, there are features that are not available in graphic windows interfaces. Using a console on a personal computer can be done via a built-in applicatikn (cmd on Windows, of bash or tilix on linux/unix). If you are not using a local machine, you need remote access to the system And that should be s very secure way to get access. Both in windows and in linux remote access built-in. In Windows it is remote access via the RDP protocol. On linux it is SSH (secure shell, where shell in fact is the name of the console). But using this built-in feature can be cumbersome. There Putty comes in handy. Putty is available for all platforms via https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
Putty makes access to remote servers quite easy, you can configure default access to multiple servers, so less ip addresses have to be entered.
Start Putty and the main screen is shown. Enter the IP Address of the server you want to connect to and press save, for reuse later. All default settings should be okay. Once you press Open, the command shell of the server is opened with a Login prompt. Beware: the first time you connect to a newly configured server, Putty asks you if the server can be trusted. If you are certain, press Accept.
That's all there is to it. If you entered your login credentials (login name + password), you should now have an authenticated session.
Another note: If you use Yunohost, you will no longer use the root-account of your server, you need to use that operator account that you created when you installed Yunohost.