Try a hard reset .
Be aware a hard reset will erase all your user data and downloaded apps. It will restore your tablet to a factory default condition. It will be like when you first bought it.
Before performing a hard reset ensure that the battery is fully charged and that the charger is not left connected to the tablet. Also remove the external SD Card (if installed).
Here are two links, which show how to perform a hard reset.
Be patient, it takes a short while to complete a hard reset.
If a hard reset does not resolve your problem, then as your tablet is only 1 week old, consult the warranty documentation that came with the tablet as to what you have to do to make a claim for a warranty repair or replacement.