Where can you find the SD card folder?

Well if your saving a picture you took go into your camera settings and select sd card card instead of phone. Or if you already have the picture on your phone then select move and then your sd card. For music I just use my pc and drag the files. Now if your looking to save games and other files you need to give your phone permission to do that. There are threads on here that will tell you how to go about doing it. They are well written and better at explaining then I could.