How to run KDE Plasm on Debian 10?

Question

linux

I put on a Debian 10 laptop with KDE, after the installation is completed, it meets the console.
I enter, I enter plasmashell, I get:

qt.qpa.screen: QXcbConnection: Could not connect to disnplay
Could not connect to any X display.

I enter startx, I get:

xinit: giving up
xinit: unable to connect to X server: Connection refused
xinit: server error

All sorts of kdm restart commands write that

Failed to start kdm.service: Unit kdm.service not found.

I reinstalled the system several times, upgraded, still the same result (no result)
The first time I decided to try KDE, but here it is, how to be?