You have all the powers that Putin currently does. Everyone completely loyal to Putin is now loyal to you. Enemies of Putin are enemies of you. Putin no longer exists, and there has been a clean and absolute transfer of power to you. 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. The world at large doesn’t know your past life, to them you have magically appeared as the new ruler. To everyone who knew you before, you just vanished.
Edit: no one knows your past life YET. They’ll quickly figure it out. You will not lose any support based on your actions in your past life.
Russians wouldn’t know what to do with democracy if you gave it to them, there are plenty of older Russians who would be happy to go back to the way things were before 1991.
There’s no trust in leadership, corruption is rife, the people know they’re being lied to, they’re used to it and expect it.
I’d GTFO as soon as humanly possible before I’d try and fix things and just end up making it worse.