Ok. What exactly is not working with the network? Are you on wired or wireless? If you do run ip a, does your interfaces show up?
Another thing to look at is journalctl -b. Look for errors, lines in red, anything about the network. If you can roll back to a functioning boot (or run journalctl -b -1 should show the previous boot) and compare to that is probably a good idea, journald (displayed by that command) may contain errors that are not relevant, so comparing to a functioning boot may be good.
Also, depending on how old your computer it, there may be another hdmi output which uses the GPU integrated to your CPU. If that is the case, you could switch to it if the nvidia card stops working just to troubleshoot, take a look at journalctl -b and look for errors again. If the screen just goes black, and does not boot, this may also give you some messages as to why the nvidia graphics is not coming up.
Shit, I'm still waiting for the day macos (I assume that is what we are actually talking about here) is usable.