Hi. The Dahua cameras come with an IP of 192.168.1.108 which you can change.
If your network is different than 192.168.1.x then you will not see them.
You can download the Dahua config tool below for windows to see the cameras and Initialize the camera(if needed first time and once only) and then set an IP for the camera to suit your network.
dahuawiki.com/images/Software/ConfigTool/General_ConfigTool_ChnEng_V4.09.0.R.20171010.zip