Has anyone else used Linux

So I've spent some money on a Linux operating system in order to learn how to use it.

I have actually wondered if anyone has used it before. I have been installing a lot of applications on it. I have tried to install VNC viewer as seen here:


I also tried to configure lightdm as I heard that was another option but failed:


So my question is how do I install and run VNC viewer so that it works for Mac. I have already installed it but I am unsure how to edit files. Maybe some programmer who is more experienced than me can explain how to do this.

Sorry if wrong section but move if possible.