Ethernet ports, I believe, are through an adapter. For your Dell, you would get an USB ethernet adapter. One end plugs into one of the USB ports on the computer and the ethernet plugs into the other. With DS mac, it has a lightning port that plug in (like an iphone charger) and the ethernet fits in the other end.
The university packages, if you scroll down, had the adapter included, that’s how I knew I needed to purchase one.
You can get them at Best Buy and I am sure other places.