This will be a very quick read, which I think is super cool, the les you can spend time on reading and more on actual practic code etc. the better!
Log into you server under cli and install 'tasksel':
sudo apt update && sudo apt upgrade -y sudo apt install aptitude tasksel -y
Next we will install the graphic enviroment that you want, run on cli theis command:
Follow tha instruction that you will have on your screen, chose the gui you want, after all is done install one more thing, 'xrdp':
sudo apt xrdp -y
Now xrdp is the software to allow you to connect to your machine using the RDP protocol. This will be required to use the gui.
Now on your local machine just get an rdp client (depending on the version of your system this will be difrent, so you do a serach on the net for rdp clients for you system), and connect using your server IP address. You have a gui on the Linux server machine now :)