Chrome extension for gumtree

I am interested in making a chrome extension. I am not a developer but I intend to take a fully comprehensive course from something like udemy or pluralsight, before I start taking the course I wanted to know if I would be able to create something exactly like this : http://ift.tt/29kfB83

It is an extension which makes it easy to post and manger ads on a classified ad (gumtree)

I would be grateful if anyone could let me know. How easy or difficult would it be to make something of that sort.

Thanks