Raspberry pi 5 su password

Good evening, I downloaded and burned the latest raspberry pi 5 image and have run into a couple of problems.  The user "cnc" password "cnc" lacks root access and only has read access to the etc file.  Is there a SU password for this latest image.  I need to make some changes to the etc /network files as there is no apparent network manager showing in the available applications.  Thanks!

Just use.

If you want you can installthen reboot

None of the Linuxcnc images and ISOs install a root user so sudo is required
Sometimes I do: sudo su
which gives you a root access (you will see the prompt change) untill you type: exit