Microsoft Office 365, or the latest desktop versions of the software is fully VoiceOver accessible. Will take a little bit of a learning curve to navigate the app, but it's fairly easy once you get the hang of it.

I use excel quite frequently. Both google sheet and MS Excel on Windows are my go-to options. As I use ZoomText, I found that excel doesn't work well with ZoomText. I was taking accounting courses a few years back and the accessibility was a nightmare. I even spoke with the developers at ZoomText about this issue and they said they couldn't help because Microsoft would share the code to make it accessible. This was around 2015.

Since then it has become a bit more accessible. It will be quite a bit of a learning curve to use screen-reader with excel as some shortcuts don't work while accessibility software is running. Depending on which College or University you are at, their accessibility technician should be able to help you learn the system.

To get started, learn how the basic function of excel works before using a screenreader. Otherwise, it could be an overwhelming amount of information.

Accessibility support in Excel for Mac is lacking, I say this as someone who generally prefers Mac applications, but you should definitely look into getting a separate Windows system, either on the Mac or as a separate machine.

I use Excel all day every day. It works great on windows with Jaws but was pretty lacking last time I checked it out on the Mac.
My vote is to get a windows partition going on your mac if possible because college level work in Excel on the mac will likely be very difficult if not impossible.

In my limited experience of supporting a VI user of Excel, I would say it depends how your brain works.

Documents are linear in nature, they start at the beginning and move a sentence at a time towards the end. Hypertext has complicated this picture but most navigation of hypertext documents is still a simple tree like structure. Keeping track of the structure, where you are and what is going on doesn't take too much memory or imagination.

Spreadsheets start out being two dimensional. Add additional linked sheets and you are trying to keep track of at least two and a half if not three dimensions of structure. You then have the equations and references: these are all address and not contents based. So rather than have an equation that reads as "equals hours times rate" or "= t * R" you have a formula that reads "equals C1 times D1" or "= C1 * D1".

Learning keyboard shortcuts, both for excel and the screen-reader is also very important so that you can access the various parts of the screen. I can't say if Excel in the Mac is fully shortcut usable.

So there is a lot more remembering where you are and what is where. The screen reader I help with is Dolphin Supernova for MS Windows which I don't think is widely used in the US.

On windows, it works great with both jaws and NVDA, including both basic and advanced features. On the Mac, I think it has some shortcomings, but the basic features should work. I haven't needed to use excel extensively so someone else will hopefully contribute more information.