Thank you so much for your explaination! I was quite worried, but you definitely reassured me, I’m very relieved!
No problem
. Malware certainly does exist for the Mac, but you're unlikely to encounter it if you don't seek it out.
If you turn off System Integrity Protection and run random executables as root, maybe, but not as anything remotely ressembling an average user.
The closest thing I've seen to malware on a 'regular' Mac, has been a browser plugin that set Yahoo as the search engine and set it back to Yahoo if you tried changing it. But aside from being more tricky to remove than it should've been it was fairly benign.
That is not to say you shouldn't worry about security risks; Just don't worry about vira and similar software attack vectors so much. Your biggest threats are convincing phishing scams and the like.
Linux and macOS are really quite secure platforms. No OS is impervious to attacks, but you're unlikely to be in much danger on the Mac. If you're in an environment, like a an office with a shared network drive or something, with a lot of Windows PCs, you might still want anti-virus to help protect those though. I can recommend Sophos for that.
However, even Windows is a lot more secure than it used to be. Windows 10 isn't so bad on that front if you keep it up to date. Keeping up to date goes for any software when it comes to security - That is, not necessarily the latest feature release, but the latest of a supported release.
And Windows is also just the biggest attack vector as per market share. So we in the Mac camp can enjoy a more secure computing experience along with our Linux and other BSD brethren.
