Trying to create notification box when clicking a button

Trying to create notification box when clicking a button

I have been having some trouble in creating a simple notification box.
Basically the objective here when i click the submit button(input
type=button) it will display a simple notification box like this.

I have been told a plugin is not necessary for this kind of thing. I'm
still in the process of learning Javascript and would like to ask for some
advice on how i can obtain this kind of result.
I have tried using alert but it seems it cannot be styled and i need to
use jquery instead.