You have all the powers that Putin currently does. Everyone feels the same way they do about you that they used to about Putin. You have his authority, for as long as you can hang on to it. You have none of his knowledge, however. The economic, military, social and political situations are the same as they now are. You are not inhabiting Putin’s body, you are just you. You’re magically transferred to the Kremlin.
How do you avoid falling out a window onto a pile of bullets your first week?
Same way as every single other Russian transition of power in modern history:
Reveal that the previous leader betrayed the Russian people, and you’re here to set things right. EVERY transition.