Command & Conquer : Reborn

When my dad starts up a server, all he gets is GAMEPLAY RENDERING and nothing else. How can we play together on LAN?

Are you sure it doesn't say "gameplay pending?" If it does there is an option in the game hosting screen called "Dedicated Server". It is a check box. If this box is checked, uncheck it.

And dont forget if you want to play alone then make max players 1.
(if there would be a option of minimum players make 1 too)