Mathiews

Hi, it's been 2 years now i starting geocahing. I started to search chaches with my Iphone 4. This week, i bought a garmin dakota 20 GPS. I must learn to transfert GPX to my device. I know the green button to tranfert cache at once, but can we tranfert a lot of caches simultaneously? Does i must make a pocket quesrie? How can i do that? thank you!