You can choose which apple variety you want, depending on what you want to use it for. If you want to make apple pie, the Boskoop is the right variety to use. If you are going to eat the apple directly, Topaz or Braeburn are better choices.
Apples should be stored in a cool place at home if possible. In farm shops, the apples are often sold in a foil bag. It is best to leave the apples in the foil bag when stored at home. If the temperature is low, the apples can last for weeks. The apples become less strong at summer temperatures. In addition, the apples may spoil due to dehydration.
Some apple varieties form a natural fat layer on the peel in order to protect the fruits from drying out. These apples work as if they are waxed. This is a natural process, though, that occurs with the varieties Jonagold and Topaz for example. The waxing of apples is not allowed in Germany and also not necessary.