how best to update early 2015 macbook air
I have a macbook air early 2015 that's high sierra 10.13.6 version. What's the best way to update it the OS? It's working fine now, though sometimes at work, I can't use the wifi anymore, I'm guessing because my OS is outdated. I'm a little worried that if it ain't broke don't fix it. I rarely take it to work anyway and have other computers I can use, but the other concern is security, of course. So two questions: Is it worth trying to update? If so, what's the best, foolproof way to do that?
Earlier Mac models