How to create newsletter subscription (notification)

[Jean]

Hi,  

 

I want to know , if it possible  , to create  a message on the homepage, to newsletter footer,   '' you are successfully subscribed ''  

On My default theme,  you see  nothing happens,

 I receive    the  customer his email  , but not the  message  ,   '' you are  subscribed to or newsletter" 

This is very confused ,  for customers   so witch file  , must  I edit  , too make this happen ?

 It requires additional coding to display the message "you are successfully subscribed" below newsletter form.

But where must I edit this ? 

Thanks. for help, Jean 

Edited October 12, 2019 by selectshop.at
removed mass capital letters on title (see edit history)