Why I can't edit this page?
here is the edited version
The first place you can ask for help is the FreeCAD forum (Please read this post before asking any questions). There are different subforums for FreeCAD developers and users. Make sure you search the internet before you ask for help and read through the existing questions that have already been made and/or solved. There are also subforums, where you can discuss other subjects, give your impressions of FreeCAD, ideas, etc. The forums are both very active and you should get a reply very quickly.
If you need help or have questions related to a particular page of this wiki documentation, you can always leave ideas or comments on the "discussion" tab of each page.