Lilian If you go to your Amazon account at Amazon and from there to the Kindle Store and then to "manage your Kindle" a copy of your books should still be there and you can download them again to your Kindle.
If it will not do any wi-fi-ing at all, maybe it thinks you are still at your daughters and is looking for their wi-fi - you do have to tell it which wi-fi connection to use.
Do you have any wi-fi at your house? If not, try taking it to your nearest public library, they probably have a connection you can use, and they might be able to sort it all out for you too. Tell them you got it for Christmas and throw yourself on their mercy.
Most of them do courses for beginners at computers, so they are used to untangling stuff and explaining things.