This site is actually pretty simple, just need to know your way around.
To post a thread (like you have here), just open the thread you wish to post to, and scroll to the last post. You will see the 'reply' box and that's where you type your post. Then, when you're done, just submit. However, you have already figured that out I guess since your post is showing here.
If you wish to start a NEW thread, rather than reply to an existing one, the process is much the same. Go to the forum you wish to post in (ie: singles, bible discussion, suggestions etc) and click on the icon at the top which says 'NEW THREAD' and type away.
To use chat is simple:
At the VERY TOP of the forum page (above all these forums- right under where it says CHRISTIAN CHAT on the home page), there are a bunch of options. Go to those options and select whether you wish to use a webcam or not, if youwant volume or not etc (it's all multiple choice) then click the big CHAT NOW button, and you're on your way.
Hope that helps!