Which is the help menu in Computer?

Help and Support. Opens Windows Help and Support, where you can browse and search Help topics about using Windows and your computer. See Getting help. from the right pannel of the Start menu

or

Press F1 to get Help for Window and any other software

or

You have find help menu option at the last item of every software or any window's explore

Press F1 key in the specific program will provide the help menu.

or go to File options last item.