Beginner Linux® Desktop users often consider what is the best desktop environment to useful to them. I can tell you which is the best it, but it is depends on your machine.
GNOME and KDE are "Rich desktop environment". It means that if you have a "Rich spec machine", it is the best way to choose desktop environment. I mean "Rich spec machine" has quad core CPU, above 8GB RAM and SSD. If the machine has them, beginner Linux users will be useful manipulate experience.
Xfce and Mate are "Affordable desktop environment". It means that if you have a "Affordable spec machine", it is the best choice desktop environment. I use MATE desktop environment by old desktop machine. "Affordable spec machine" means that it has dual core CUP, above 4GB RAM, and SSD. I think HDD will be good to work Xfce and MATE, but sometimes they are not good to work. I recommend to use SSD if you use Xfce or MATE.
LXDE/LXQt are "Lightweight desktop environment". If you have low spec machine, I definitely recommend it because it really lightweight. Low spec machine means that it has low spec CPU, above 2GB RAM, and HDD. Thus, I recommend it if you have old PC, please try to use it.
If beginner Linux desktop users do not make a decision about choosing Linux desktop, they should choose Desktop Environment is the best way of adjust their machine.