Sage For Mac

That is not a Mac program. Its system requirements say it is for Windows computers:

https://www.remoteaccounting247.com/modules-system-requirements-sage-50-hr/

That is not a complete deal-breaker. Your options depend on what OS you now have on your Mac. "iOS 11.2" as shown in your equipment profile cannot run on any Mac computer, only Apple's mobile devices. Please do "About this Mac and tell us what Mac OS version that reports.

First, you posted in the forum for iMacs made between 10998 and 2005. Is your that old? None of the solutions below will work on Macs that old. So please clarify by telling us your sub-model, also from "About this Mac." Sub-models usually will include a date, like "iMac Late 2012" or "iMac Mid 2010"

It is possible to either run Windows on a Mac natively or emulate it, but you usually have to buy a legal copy of Windows OS to do so. The most stable option is to use Apple's Boot Camp. Information here (click): Boot Camp - Apple Support

Products like Wine (WineHQ - Run Windows applications on Linux, BSD, Solaris and macOS) or CrossOver (https://www.codeweavers.com/products/) can run SOME Windows applications natively. Check with each developer to see if your accounting program is supported. These two options tend to have support bundled for the most popular Windows programs like Office and Explorer but not obscure specially programs.

Emulators are Mac apps that allow Windows to run like a Mac program. Fusion and Parallels are the most common. However, as with Boot Camp you must purchase a valid and compatible copy of Windows. Emulators are often slower and may not do graphics well. That could affect creating charts. What version you get depends on what OS is now installed which, again, we do not know.

Given the expense of a legit copy of Windows of the proper kind, you may be better off to seek another solution that is Mac-native. They are out there if you search "mac accounting programs"