Hi, I'm Nathan.Sorry to hear that you're having trouble, but I'll do my best to help you. Please give me a few moments to review your details here.
This symptom can indicate several possible issues: an internal hardware failure, a low/faulty battery, or just a simple memory/firmware glitch.
The first step here will be to attempt to reboot the kindle. This is done by pressing/sliding and holding the power button for 20+ seconds, or until the screen flashes (usually with an image of a tree), then release. Give the kindle about a minute to start back up, and let me know if the problem persists, we can then try some further steps.
Sorry I missed you last night, I'm in the US on a much different time zone.
Do you mean how can you sort them?
Sorting and organization, other than alphabetical, is somewhat limited on these kindles.
The best way to do this is by grouping them in "collections".
Here is a detailed guide to that process: https://www.amazon.com/gp/help/customer/display.html/ref=hp_left_ac?ie=UTF8&nodeId=200953940
Typically the kindle can hold several hundreds, but there are a lot of variables based on size and images contained.
You'll know if it gets full as it would give an error message, but even that is rare - the kindle will manage its space automatically and remove older titles that are not needed immediately. All your books are always stored on the amazon cloud servers, so you can download them again anytime at no cost.
If you have any other questions, just let me know. Otherwise, please take a moment to rate my service as this is the only way I am credited for my time. Hopefully I have earned 5 Stars but if not please let me know what I can do to ensure you are satisfied. I also invite you to contact me directly with any future support needs at http://bit.ly/1QwLxGh and ask for Nathan.
Thank you, ***** ***** a nice day,