Hi, completely new to Linux.
Core storage minimum requirement is given as 15Gb.
But what are
More than enough. You'll be fine. Relax.
Unless you are installing a lot of games and such, 100Gb will be enough.
As a precaution, when installing software through the Store, pay attention to the "source" and prefer the option labeled as "Zorin OS" when available.
Since you are new to Linux I don't want to bore you with details but you'll likely face fewer problems, by doing this, including regarding disk usage. But don't worry too much if you have to use any of the other options, it's just something that I recommend doing whenever possible.
Here's an example of what I mean, note the various options under the "install" button:
As @zenzen says, keep away from snap and flatpaks when you only have 100GB or keep it at minimum of apps to that format.
Welcome to the Forum!
I guess Core means Zorin Core Edition. And there You need at least 15GB to install the System.
Depending if You first want test Zorin and You don't directly put dozens GB's of Games, Movies, Pictures and Music in the System, 100GB should be more than enough.
I usually recommend no less than 64gigs, due to the expansion and growth of package and file storage over time. Others have already outlined the things that can more drastically increase storage need.
Since a maximum would be more dependent on use cases; this is tougher to assign a numerical suggested value.
A person storing many games, movies, photos and other size heavy files may want to stick to less than four terabytes. A person that uses the web only, browses and keeps few files around would be better off sticking to less than 900gigs.
Reasons to set a max:
You've just reminded me why I prefer HDD's!
