Hi, welcome to MR from the Netherlands. If I ask too obvious questions, excuse me for that: did you fully charge your Kindle and did you press ' home''? You could also try a reboot (hold the on/off button for 15 sec. to the right, then wait till it reboots.....a little patience---and you see the guy under the tree with the empty space under it and the Kindle fills itself with your books).
Often that helps; if not, ask on the Kindleforum and you'll get some good answers.
