There are different subforums for FreeCAD users and developers. Make sure you search the internet, and read through existing questions before you ask for help. There are subforums where you can discuss more specific topics, give your impressions of FreeCAD, discuss new ideas, etc. The forums are 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. To upload files for Wiki please use this page.
Internet Relay Chat (IRC)
There is an IRC #freecad chat room on Freenode. #openFOAM-IRC is also on Freenode.
If you are on Reddit you may use the r/FreeCAD, or the r/flossCAD using the FreeCAD flair. The r/flossCAD subreddit also has a chatroom where might be able to ask questions. There are also r/ElmerFEM, r/openscad, r/LibreCAD/ r/OpenFOAM, and r/Modelica subreddits.
Twitter and Mastodon
You may join the FreeCAD's Facebook public group
There is an unofficial Discord channel on Elmer's server where you can ask questions, showcase your great work and get feedback, and even share videos messages. There are also Discord servers for Modelica Language, Elmer FEM, and OpenFOAM. Please do not use chat groups as the main medium of exchanging data. They are not indexed by the search engines and information produced on those platforms is not properly accumulated, as it does on forums.