A password box is simple enough. If you want to display this as a dialog then you can use something along the lines of
Dim sPass as String
sPass = InputBox("Give me your password")
To get a graphic out of Access you might explore using a mailmerge field although that is possibly not in the spirit of the assignment. The best source I ever used for learning VBA automation of other office programs was the code samples provided by Helen Fedemma which can still be found here
http://www.helenfeddema.com/Code%20Samples.htm
Those code samples may be old but if you pick over those bones you should learn enough to complete your assignment and perhaps ask more focused questions to get over any hurdles you may encounter.