how do I update iphone 6 to be safe from these new problems that are on the news?

Your iPhone 6 cannot be updated beyond iOS 12.X. It’s simply too old.

What new problems?

Hahaha that’s funny it’s 2021

A whole new iPhone or current or up to date

newer model is best option get that iPhone 6 away from you far away it’s ancient and try and swap it for a credit towards new one. But it’s 2021

Even if it was 2050, old hardware cannot run new software designed for a completely different architecture. (excluding hacking and weird finagling)