Hello Chagrs,
Even being French you should be able to pick this up pretty quickly. 
There should be a link to the github repo where you can find a zip file to download with the code. Just download that, unzip and you should be good to go from there.
A couple things you will most certainly need to know is python programming and how to set up your environment for that. It would be very useful to know how to use github also. It’s very useful and full of free code that you can use and read to figure out how to do things. I’m 55 and have been programming since I was 8 years old and have only every looked at others code and read books.
Videos on you tube about getting started with Python and OpenAI will help you greatly too. Don’t dive to deep at first, as it can get pretty complicated fairly quick.
Good luck to you.