According to me you do not want any additional circuitry for your ping ultrasonic sensor except a voltage divider. The physical pin 2 and 4 of Raspberry Pi zero give you 5V power and you can expect pull about 1.5A from these pins. But you only want 30mA to 35mA for the working of this sensor according to datasheet. So we can assume that there is no problem with connecting physical pin 2 or 4 of your Pi to Vdd of ping ultrasonic sensor directly. You can connect Pi's physical pin 6 (ground) also directly to ground of ping sensor. Then the problem begins.
Now you want to make signal(SIG) pin as input. From datasheet it is clear that signal pin output can have up to 5V. But the 5V as an input to GPIO pin can harm your Raspberry Pi. Since it GPIO pins are 3.3V(CMOS logic) tolerant. So you want to make a voltage divider between GND and SIG pin using two resistors R1 and R2.
If the resistances of R1 and R2 is same then the voltage splits in half(2.5V) since the maximum possible SIG is 5V. If the R2 is the twice the value of R1 then we get 3.33V approximately which is fine. So ideally we want R2 to be between R1 and R1 x 2. In this circuit we are using 330 Ω and 470 Ω resisistors. Alternatively you can use 270 Ω resistor and 330 Ω resistor or 1KΩ resistor and 1.5KΩ resistor. Then you can connect the SIG input to RasPi GPIO pin from junction of R1 and R2.
I am very new in Raspberry Pi. So you should critically think about this answer. I believes Raspberry Pi Stack Exchange community will help you to think critically about this answer.