setting up wp-server chat forum

Ok so i may be being slightly thick in my understanding of how installing a forum works….
I have a quite good understanding of wordpress and brief coding knowledge.
I’m creating a website for a mate with a new startup business. It has a members area that has username/password protection.
Within this section i want to have a forum where clients can post comments/thoughts/questions etc its all part of the service he wants to offer to his clients…
I created a page called Client Chat expecting to install ‘wp forum server’ and be able to select this application to run on this page!
That hasn’t happened and i cant find where this forum is showing!!?!

Would be most greatful if anyone understands my predicament and could point me in the right direction of how to make this possible, that’s if it is?!