Most networking courses assume students are running Windows in my experience. The best thing to do is find out from the instructors what tools they will be using, and plan based on that. Cisco's Packet Tracer, for example, is popular in Cisco related courses. GNS3 is somewhat similar but more flexible and open source. My guess is you'll be running one of those, or both.
I would strongly suggest setting up a home lab and playing with this stuff on your own. The courses are an introduction, but practice and mistakes will get you much farther. For that, I would recommend a laptop with USB A ports and built in ethernet. Connecting to networking equipment in your lab will mean using either DB9 serial ports, Cisco style RJ45 serial ports, or ethernet cables. Doing that through Apple's ridiculous dongle mess is going to be a painful experience.
As far as brands go, I like ThinkPad T series laptops, but the Dell Latitude line is popular too. Get something with at least 16 GB RAM and 4 cores if you will be running GNS3. More is better.