I've used AVAST free for several years and was pleased with it. You are absolutely correct, proper online browsing practices can help protect you from a lot of unsavory experiences. I'm using AVAST Pro currently, but I've read some good reviews of Windows 10's Windows Defender.
One application you will probably wind up with is a PDF reader. Adobe Reader has been around for years and is used by many people, but it has a large footprint. There are a couple of other applications which work quite well, Foxit Reader is one example.
Most people will have at least one other browser other than Edge used in Windows 10. Two of the more popular browsers are Google Chrome and Firefox.
Another application you may wish to include would be a email client. There are several to choose from here as well. I'm currently using Mozzila's Thunderbird, but there are others such as Opera Mail, eM Client, Claws Mail...
Edited by dc3, 21 October 2016 - 09:23 AM.