Hello 
I would really like to replace MacOS with Zorin on my 2012 MacBook Pro & I'm trying to get started by setting up for dual-boot 
I haven't tried a cabled connection, because there's no network port on this machine & I don't have a USB network adapter.
Is there any way of installing without having to acquire such an adapter...?
Hello there!
While I would recommend getting a USB WIFI adapter just to be sure, (Their good to haves for backup too) If you do a full install with drivers, Zorin should come with a WIFI driver in the kernel, to get that WIFI going.
If it were me making the decision in your case, I would opt to get a cheap WIFI dongle for that thing, just to be on the safe side. Heres a link!
Did You take a Look at the ''Additional Drivers'' Tab in Software & Updates if there is a Driver for Your Wifi offered? Could You post the Output of sudo lshw -C network please?
You likely have a Broadcom card on MacBook which is Proprietary with its drivers.
Using your Phone as a hotspot with USB tether to connect to the net, launch terminal and run
sudo apt install firmware-b43-installer
sudo apt install linux-firmware
Using a USB-tethered phone was a great tip, I hadn't thought of that - thank you @Aravisian 
I also made some progress downloading & installing the Broadcom driver - until I realized that this would probably require a restart & so wouldn't work from the Live USB.
No worries, for now at least - I can run the installation with the phone tether & then do the other thing.
That should probably be a different thread, though, with a reference to this one? I would like to share my experience with it, just in case someone else can use it
Because it is the same Thing, You can share the Progress here. It don't think that it is neccessary to open a new Thread.
Well, in that case: It worked! 
I have installed Zorin as planned & managed to get wifi to work. It took a bit of fiddling, though - just running those two installs wasn't enough.
I got an error which, when I searched it, brought me to this thread: https://askubuntu.com/questions/1241362/fix-package-post-installation-script-subprocess-returned-error-exit-status-10-fo
I followed the advice there & got the firmware package to install, rebooted - and it still didn't work, so I searched again, found this thread, and followed it slavishly: https://askubuntu.com/questions/55868/installing-broadcom-wireless-drivers
Apparently that did the trick
Some of the steps were redundant, of course, because some of the above steps had already covered it, and being new to Linux I can't say for sure which steps did what - but it works now.
Thank you for your help - I'm glad to find that this is a friendly & responsive forum, another reason to believe I chose the right kind of Linux 
