This is slightly off-topic, but you seem to be a little mistaken as to the role of an Antivirus program. Put simply, they're the ambulance at the bottom of the cliff. They attempt to remove viruses from your PC when you're already infected, and generally are worthless at actually preventing the infection in the first place.
Of course, an ambulance is better than nothing, but a much better solution is to practise good security hygiene in your daily usage of your PC. This is the main way you can prevent infection in the first place:
- Don't open email attachements unless you're sure you know what it is (it came from a friend AND it's just a PDF or word document, etc)
- Don't open .exe attachments, ever
- Don't install shady programs, and don't pirate.
- Don't download stuff from porn sites.
- Don't click ads. Even better, install "Ublock origin" to get rid of ads altogether, and disable it on sites you trust and want to support (like geekzone ;))
Antivirus programs are often worse than nothing, because they are gigantic sprawling programs which try to do tonnes of things, and do it all badly. This leads to security flaws which can actually *allow viruses in* where they were not allowed in before you installed antivirus. A large number of these security flaws have been discovered recently, in major products like McAfee and Norton. Norton in particular has a very bad reputation, although I don't know how bad current versions are.
Most geeks just use Windows Defender, a simple antivirus which is included in and turned on by default in Windows 10. Windows 10 is very secure by itself, and most viruses must be allowed in by the user, and can't get in by themselves.
Oh, and metered mode won't affect the security of your computer, as you're only preventing Norton from downloading new 'virus definitions', which teaches Norton which files are viruses, and should be removed. As I say earlier, it's better to avoid jumping off the cliff than to have a super awesome ambulance at the bottom :)
(And norton is not super awesome. Ugh.)