Below are Microsoft Word 365 keyboard shortcuts I find very useful.:
General Shortcuts
Create a new document Ctrl + N
Open an existing document Ctrl + O
Save a document Ctrl + S
Close a document Ctrl + W
Undo an action Ctrl + Z
Redo an action Ctrl + Y
Formatting Text
Bold Ctrl + B
Italic Ctrl + I
Underline Ctrl + U
Increase font size Ctrl + Shift + >
Decrease font size Ctrl + Shift + <
Navigating the Document
Move to the beginning of document Ctrl =+ Home
Move to the end of document Ctrl + End
Find text Ctrl + F
Find and Replace Ctrl + H
Go to a specific page Ctrl + G
Editing Text
Cut Ctrl + X
Copy Ctrl + C
Paste Ctrl + V
Select all Ctrl + A
Working with Tables
Insert a new row below Ctrl + Enter
Move to the next cell Tab
Move to the previous cell Shift + Tab
For a complete list of keyboard shortcuts head over to Keyboard shortcuts in Word – Microsoft Support. I hope you find this article to be very useful.