How can I find a manual covering Microsoft Word current edition

There is no such thing, and if there were it would fill a bookshelf.

Sorry. There are, though, books that accomplish a lot.

My favorite is the Word 2010 Bible by Herb Tyson.

Another good one is Microsoft Word 2016 In Depth by Faithe Wempen.

95% of Word has not changed in years. Either of these will be useful for you.

I also recommend this short series of tutorials by Shauna Kelly.

You are welcome to ask about particular features here and likely can get good references.

Note also that there are a number of programs put out by Microsoft, all current, all named "Word." There are very real diffences. Here is a link to my pdf on these.

Publishers and authors are reticent to spend the time and resources to write books on programs that keep changing. When they do, they are pricey and tend to have a very short sales period. You may be hesitant about my recommendations because they are all dated. However, for most users they will guide them to the features they need to be using with good directions on how to use them.