Business card template – colours won’t change

There's no need to create a word doc - you can drag and drop images here and put the whole story - but no harm I guess

It looks like you've selected the Stroke to be changed

If you want the background fill to be changed you need to select it in the Tool bar by selecting on the Foreground swatch, which is behind your Stroke swatch. 

Here you're changing the Stroke (border around the fill)

As for how they created the Text effect - it looks like a Gradient to me. 

Plenty of tutorials on how to create shiny text with gradients out there. 

Let us know if you need anything else or more in-depth answers.