I understand you mistakenly loaded a fraudulent website which led you to granting remote control of your Mac to a criminal. Is that correct?
First the bad news. Protections, lockdowns, firewalls, encryption etc are all utterly irrelevant when someone is actually using your Mac. As far as your Mac is concerned, it's you who's using it. Even though it may have been accomplished through deception, granting control of your Mac over to a remote user is no different.
If there is any good news you will have to use your own judgement to decide if your personal information has been compromised. At a minimum you should be using Apple's two-factor authentication for your Apple Account: Two-factor authentication for Apple Account - Apple Support. It's difficult to do anything at all with Apple these days without having it turned on, so I would be surprised if you are not already using it.
All we can do on this website is speculate whether someone did something nefarious to your Mac. There are literally no tools, utilities, apps, etc to absolutely positively rule that out. None. Don't bother looking for one. Having said that, most criminals who attempt to exploit neophyte computer users are seeking the low-hanging fruit of credit cards, bank account information, that sort of thing. Your Apple ID and its password are also valuable commodities that should be guarded just as you would anything of value. Never divulge that information to anyone.
Only you can know if you divulged that kind of information, and only you can know what you may have observed that criminal do from afar as you watched.
At an extreme, there is no remedy for this kind of common exploit other than to completely erase the Mac. I say that primarily to preclude the multitudes of shrill Internet denizens eager to point out erasing a Mac is the only way to provide absolute 100% assurance the criminal did not deposit some obscure nastiness on it, which can be challenging to find even with an in person, hands-on exhaustive inspection of it, a task that is obviously impossible over a website such as this one.
I would like to tell you "don't worry, it's probably fine" which is likely to be so... but it's your Mac.
