Since you don't have an idea on electronic, this may be overkill. Just use a simple LM3915 chip for a easier VU meter.
Here is a simple code for an arduino VU meter. You can use any amount of LED's, just trim the code (lastLED)
int sound[4];
int soundav;
const int inputPIN =8; //audio input pin, gnd other end of 3.5mm jack
const int firstLED= 34; //first output pin for leds
const int lastLED = 53; //last output pin for leds
int leds;
int x;
int y;
void setup ()
{
pinMode (inputPIN, INPUT); // put input pin in input state
for (int a=firstLED; a <=lastLED; a++){ // loop output state
pinMode(a, OUTPUT);
}
leds = (firstLED + lastLED) +1; //total leds + 1 for off
}
void loop ()
{
for (int num=0; num < 4; num++) {
sound[num]= analogRead (inputPIN);
if(num==3) {
soundav=(sound[0]+sound[1]+sound[2]+sound[3])/4; // average level
x = map(soundav, 1, 255, 0,leds); // 0 to 20 sound levels
y = firstLED + x; //correct pin required
for (int b= firstLED; b < y; b++) { //loops all leds from firstLED to sound level
digitalWrite(b,HIGH);ll
}
for (int c = y; c <= lastLED ; c++) { //loops all leds from lastLED to sound level
digitalWrite(c,LOW);
}
Good luck.