DFPlayer mini mp3 player Random track

Other Hardware Audio
4

I don't know what all you've done so far. And you failed to "post your code".
I've seen lots of problems with these things lately. I had a few stashed for over a year, pulled one out and it worked for me first time out.

Reformat the SD and put 2 short MP3s on it, name them 001.mp3 and 002.mp3, copying them to the SD one at a time.
And then get the player going right without other complications,

#include "SoftwareSerial.h"
#include "DFRobotDFPlayerMini.h"

// Use pins 2 and 3 to communicate with DFPlayer Mini
static const uint8_t PIN_MP3_TX = 2; // Connects to module's RX 
static const uint8_t PIN_MP3_RX = 3; // Connects to module's TX 

SoftwareSerial softwareSerial(PIN_MP3_RX, PIN_MP3_TX);
DFRobotDFPlayerMini player;

void setup() 
{
  Serial.begin(19200);
  softwareSerial.begin(9600);
  if (player.begin(softwareSerial)) 
  {
    Serial.println("OK");
    player.volume(22); //30 is very loud it seems
  } 
  else 
  {
    Serial.println("Connecting to DFPlayer Mini failed!");
  }

  pinMode(13,OUTPUT);
  digitalWrite(13,LOW);
}

void loop() 
{
  Serial.println("Playing #1");
  player.play(1);
  Serial.println("Pause . . .");
  delay(2000);
}