I would say that the best way to practice copywriting is by copywriting :) Books are mostly about theory and without practice they are useless.
I read and could recommend the following:
Elwyn Brooks White - Elements of Style
Vic Schwab - How to Write a Good Advertisement
Gary C. Halbert - The Boron Letters
I can't recommend a book because I have not read one.
But, you should check out marketingexamples.com
You will find tonnes of inspiration and ideas from there.
Happy learning :)
They will gather all the information for you, create an outline pick the perfect topic and even some nice pictures for more detail go through the provided link https://www.queronaao.com/ in this link the only thing that you will have to do is to put all this together in a text which should not be as difficult as you think now.