Using Microsoft word for iOS 10 editing questions

Does anyone have experience using Microsoft Word for iOS? I installed it on my iPhone seven but can't figure out how to edit pre-existing document. I am using a Bluetooth keyboard it is not an Apple keyboard. I have trouble it seems that editing documents on the iPhone. The best way for me to edit them is to create them there. If anyone has any insight or I can point me in a direction for locating sources for editing pre-existing documents please let me know. I have been looking and as of yet have not found anything to help me learn keystrokes or touch screen gestures for placing the documents in MF word in edit mode. Thank you. :-)