Getting voltage and current values into analog input

Using Arduino Programming Questions
#1

Hello, I want to get current and voltage values to input into my Arduino UNO at A0 and A1.
At first i was happily coding until when I was about to test it out using a DC power supply. It stumbled upon to me that how is my code/arduino going to detect the current and voltage values. Question is how can I separate the current and voltage so that it can be read by the circuit. Below is a part of the code, it is fairly simple. My problem is that I need help with the hardware, getting the voltage and current values into the ADC I hope someone can help me with this problem.

float pv_I; //input current
float pv_Vnew; //input voltage

void reading(void)
{
  pv_I = analogRead(A0);
  pv_Vnew = analogRead(A1);

  reading_value[0] = pv_I;
  reading_value[1] = pv_Vnew;

  Serial.print("Current, Voltage: "); //Start of string

  for(int i = 0 ; i < 2 ; i++)
  {  
    Serial.print(reading_value[i]);  
    Serial.print(", "); // Seperate each value with ',' to identify them seperately
  }

  Serial.println(" END"); // End of string
  delay(500);
  
}
#2

Generally the HW for voltage measurement is quite simple. It is just some resistor divisor (two resistors, eventually capacitor to stabilize input) to obtain required voltage range. Here is also important to choose voltage reference, e.g. internal band-gap reference for better accuracy or just VCC if it is enough.
Second problem is to measure current. Slightly more difficult. Modern circuits uses active differential amplifiers to measure voltage loss on shunt. I could recommend current sense amplifiers like AD8211, INA169.... Their use is not difficult and should be clear from the datasheet. It requires resistor shunt about 0.1ohm or less, so power dissipation is not big at quite high currents (1,5,10A).

#3