Am I right with select of base resistor?
Your circuit has some problems, particularly that there is nothing pulling the gate of the FET high when the transistor is off.

However, you don't need Q1 at all.  If M1 is indeed a P channel FET that can work well enough with 5 V base drive (I didn't look it up, but that's how you are trying to use it), then just control it directly from the 0 to 5 V digital output.  Driving the digital output low turns on the FET, which powers the load.  Driving the digital output high turns off the FET, which removes power from the load.  Yes, it's that simple.

Added

 I want to put on sleep the Arduino. So I need to put LOW the GPIO when goes in sleep.

No, you don't.  Any competent microcontroller can set it's pins high, low, or sometimes to high impedance when sleeping.  Pin state can't be changed during sleep, but the polarity is arbitrary.

A single P channel FET that works with 5 V gate drive is still all you need.

Added 2

Atmega328 sleeps, if pins are HIGH his comsumption is bigger than they are LOW.

I'm not familiar with the Atmega series, but this doesn't sound right.  Unless you can show me the datasheet snippet where this is stated, I simply don't believe you and conclude that you misunderstood something.