My Garmin Nuvi 255w won't speak TTS ( it will not say the street/road names.)?

I just bought my first GPS Garmin Nuvi 255w. I tried it for the first time today. It is suppose to name the street names in the directions, AND IT DOES NOT ! It just says turn left/right at so many feet, etc. Is it a faulty unit or am I doing something wrong? I couldn't even find Walmart on it and I was just across the road from it. ( I was just playing with it ) ;-) Other Walmarts show up---50-60 miles away. Why wouldn't MY Walmart show up on the thing. It did take me to my destination, but it didn't name the streets/roads. It won't even say my home street name. Can anyone please offer any helpful suggestions as how to set it to say the street names. I'll give you 10 points if you help me get it set correctly.

Also, is there a way to set it to not give me the shortest distance routes so I can take the main highways and not the off roads?

Thank you!

JOHN 3:16