There are several good security apps, and most articles like this recommend you try before you buy -- note that you should look for & download the company's own removal program in case you decide the software's not for you, since a regular uninstall can leave too much behind [security software is intentionally hard to remove because some malware will try to remove or disable it].
zdnet[.]com/article/best-antivirus/
Windows builtin Defender may be enough, probably has the least impact on system performance, & has top ratings in tests from sites like av-test[.]org -- I use 3rd party security software because I feel Defender is more targeted by malware since it's installed with every copy of Windows, but that's me. On our lower powered devices I run McAfee, which also has top ratings, because it has less impact when you're running something like a lowly Atom or i3 CPU. BUT, McAfee can be expensive & is less often on sale -- I've been buying their LiveSafe package, which covers an unlimited number of devices, for $10 from Office Depot during their Black Friday sale.
But McAfee can be a little intrusive sometimes, so we run BitDefender on our more powerful PCs -- it's just far too much in my experience on our low powered [cheaper] devices. And Bitdefender is very often on sale for around $20/year for 3-5 devices. I think Android cell phone protection is usually included with security software packages -- my wife's been using McAfee on her phone for years now.
That said, the big problem with Android when it comes to security is that updates have to come through the manufacturer, & then in the US, often through the service provider itself, so you *may* get updates for a year or two, but that's often it. As a result you have situations like the recently discovered flaw in the Apple Lossless Audio Codec. "Check Point estimates that two-thirds of all smartphones sold in 2021 are vulnerable to what it calls "ALHACK"." Google released a patch last December, but only some newer phones will ever see it.
zdnet[.]com/article/android-security-flaw-in-an-audio-codec-left-two-thirds-of-smartphones-at-risk-of-snooping-say-researchers/