Darchy, if you are using Zorin Lite (XFCE desktop) you can open your "appearance" (Not Zorin Appearance) from the app menu under settings. Then navigate over to the Font Tab.
You will see two options; Antialiasing and Hinting.
Honestly, it would be best for you to play with each setting to find the values that are best for you than for me to recommend a setting.
If you are using Zorin Core (Gnome Desktop), you will need to install an extra package just to modify the desktop:
sudo apt-get install gnome-tweaks
In the advanced settings, open it, then navigate to the Fonts Tab.
I am honestly not sure what the settings are there... I do not use Gnome anymore. But explore and ask if you have any questions.
Hope this helps.