Sorry, I should have included this information. The operating system we use is Windows 10 Pro. I have volunteered to provide IT support for our organization (7 employees some of whom are part time). We have setup administrative and standard user accounts on each computer and use Microsoft Office 365 plus a couple of other applications such as QuickBooks.
What I have learned is self taught. In any case, a local IT firm has suggested that we go the whitelist approach outlined in the tutorial. The procedure looks straight forward, meaning I might be able to implement the procedure myself. However, I wonder if I might be missing something. Ergo, my questions regarding the installation of new application and/or software updates.