install Ubuntu mate desktop

install basic software package

apt install ntp

apt install ubuntu-mate-core
or
apt install ubuntu-mate-core ubuntu-mate-desktop

install vncserver

apt install vnc4server

start and stop vncserver to create ~/.vnc/xstartup file

vncserver :1
vncserver -kill :1

modify ~/.vnc/xstartup file like

...
x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &

mate-session &

let vncserver auto start with reboot