Hi I’m new here in the forum and this wonderful application!
Study game design and programming, rather like games and plan to use the tool to create educational games. I hope this is my official tool from now. 
Where can I read the license of his use of tool (commercial)?
its open source and free to use for commercial use
HI, welcome on board ! 
Hi and welcome!
You can read a “summary” of the licence here: https://github.com/4ian/GD#license
Thanks for the welcome all!