MyPilots diagram and explanation should tell you all you want to know about traffic patterns.
You will have to be more specific about the GPS question though. I think you are referring to the blue lines that segment the land. This is to show you the different airspace you are entering and leaving. Colour varies from light to dark blue to signify the different types of airspace that you could be entering. Some areas are restricted airspace, such as that of high density traffic because they have no time for dinky little Cessna's 😞
Anything under -100fpm is a good landing in a small aircraft. Anything below -50fpm is a very nice landing, just as long as you didn't hover down the runway to make it smooth 😎
😉