If you need to work with the GUI of your Raspberry PI and you don't have a screen, mouse and keyboard for the Raspberry but for example a macOS, you don't need to install any extra software. Both systems deliver already anything you need.
The aim of this tutorial is to establish a VNC connection from macOS to Raspberry PI only with default tools of both OS.
# start the raspi-config
$ sudo sudo raspi-configSelect Interface Options
Select VNC Options
Enable VNC
Select Display Options
Select Resolution Options
Select DMT Mode 85
If all options are set, reboot the Raspberry device.
# set password
sudo vncpasswd -service
# create and modify common.custom file
sudo vim /etc/vnc/config.d/common.custom
# restart vncserver-x11-serviced
sudo systemctl restart vncserver-x11-servicedThe content of file /etc/vnc/config.d/common.custom.
Authentication=VncAuth
To start the VNC connection, simply press command and space keys. Type screen Sharing and hit ENTER. Insert the IP of your Raspberry PI and press button Connect. At the last step insert the password and continue.