Using (dynamic) text in the Blender game engine requires a few steps: defining a texture with bitmaps of the font which you want to use, mapping this to a plane, and setting the correct texture type. It's not very complicated, but it's one of those things someone needs to explain to you, I guess. This short tutorial by Andrew West takes you through it step by step.
You're blocking ads, which pay for BlenderNation. Read about other ways to support us.