We all have different approaches and preferences to securing our technology, so feel free to do as you wish, however please do something! I don't believe any platform is secure enough, whether it be Windows, Mac, Linux or your phone. I do use multiple products but my main solution for personal devices is Norton Security.
I am currently using Norton Security Premium but have a look at NORTON™ - Antivirus Software and Spyware Removal and see what suits you, or choose another product if you prefer.
Recently I had to upgrade from a 5 device license to a 10 device one, this meant I got a new Product Key and hence my subscription expired and a new one started, so all my devices started asking me to renew. Norton Security is managed via Norton - Manage Your Norton Products. So I could login, find my Windows devices via "My Devices", select the "Manage License" and update it with the Product Key which is on the "My Services" page. This worked really well as the laptops would then just update themselves, so that was easy. However the Android Phones did not have the "Manage License" option! I think the best option here was to uninstall Norton Mobile in the Play Store App the then re-install it, you will then be prompted to login to your online account and at this point it gets the new license and everything is happy again. Having done this I am now seeing a "Manage License" option, so hopefully this won't be a problem again! Do note that the portal does take time to update, so, logout and give it 5 minutes before checking again.
See Norton Community for all the latest product announcements.
If you wish to check all your Norton products are up to date then visit Norton Update Center which gives you a link to download a small app which does the checking for you. However it is better to use the product's built in checking to be honest.