Access CentOS from the other machine (via VNC)

On target machine

yum groupinstall "GNOME Desktop"

Set default target to GUI:

systemctl set-default graphical.target

yum install tigervnc-server xorg-x11-fonts-Type1

Choose a VNC display to use for accessing this particular computer (here we'll use display 5 which equals to the port 5905)

cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:5.service

Add user (if you need one) whose Desktop will be accessed:

adduser admin

passwd admin

Access file:

vi /etc/systemd/system/vncserver@:5.service

Then:

1. Go to [Service]
2. ExecStart  - here - change <USER> with admin
3. PIDFile - here - change <USER> with admin

firewall-cmd --permanent --zone=public --add-port=5905/tcp 

firewall-cmd --reload

su - admin

Execute vncserver command to assign VNC password for needed user (admin in our case)

systemctl daemon-reload 

systemctl start vncserver@:5.service

systemctl enable vncserver@:5.service

systemctl status vncserver@:5.service
Check that vncserver is listening to the ports other that localhost:
lsof -i -P | grep -i "listen" | grep Xvnc

If some kind of problem appears do below:

Remove not needed VNC display sessions (if any):

rm -f /tmp/.X11-unix/*

rm -f /tmp/.X*-lock

systemctl restart vncserver@:5.service

ps aux | grep vnc

On client machine

yum install tigervnc

Open TigerVNC Viewer (Applications > Internet) or vncviewer (from bash)

Specify serverNameOrIp:5095
Specify VNC password
then login using needed login and password (admin in our case)

Use F8 to make full-screen and to change other settings.