Wiring 8x8 dot matrix LED display

I wasn't able to find a tutorial that clearly tells how to wire 8x8 matrix of LEDs.
I'm following a guide/textbook lesson but they don't go into details how to wire it to Arduino.
A link to the specs.

One side of pins has a label "YS" and a plastic semi-circle but I don't know what to make of it. If I orient this side to be the top, where's the pin 1? I tried orienting it multiple ways but code that was supplied doesn't work at all and only fraction of LEDs blink, some stay constant, some are not lit.

IMG_0194[1].JPG

There should be a mark in one of the corners or one of the edges to indicate Pin 1. The pins are numbered counter-clockwise when viewed from the top. When viewed from the bottom the numbering is clockwise.

Pin 1 as John noted, orient to bottom left.

This code should get you started

byte c7 = 2; // LD788BX-SS22 pin 13 - left hand column
byte c6 = 3; // pin 3
byte c5 = 4; // pin 4
byte c4 = 5; // pin 10
byte c3 = 6; // pin 6
byte c2 = 7; // pin 11
byte c1 = 8; // pin 15
byte c0 = 9; // pin 16 - right hand column
byte r7 = 10; // pin 9 - top row
byte r6 = 11; // pin 14
byte r5 = 12; // pin 8
byte r4 = 13; // pin 12
byte r3 = 14; // pin 1
byte r2 = 15; // pin 7
byte r1 = 16; // pin 2
byte r0 = 17; // pin 5 - bottom row

// put all pins in an array
byte columnArray[] = {c7,c6, c5,c4,c3,c2,c1,c0,};
byte rowArray[] = {r7,r6,r5,r4,r3,r2,r1,r0,};


// pins r7 - r0 will have current limit resistor between arduino and matrix pin

byte x; // used for counter
byte y; // used for counter

void setup(){
// set up the cathode outputs - HIGH = off
for (x=0; x<8; x=x+1){
pinMOde(columnArray[x], OUTPUT);
digitlalWrite(x, HIGH);
}
// set up the anode outputs - LOW = off
for (x=0; x<8; x=x+1){
pinMOde(rowArray[x], OUTPUT);
digitlalWrite(x, LOW);
}

void loop(){
// do  a loop within a loop to cycle thru all LEDs 1 at a time
// should LEDs blink on/off across the matrix, from left to right, then top to bottom
// turn on a row
for (x= 7; x>=0; x=x-1){ // row selection
digitalWrite (rowArray[x], HIGH); // turn on cathode
  // then turn on 1 column
  for (y = 7; y>=0; y=y-1){
    digitalWrite (columnArray[y], LOW);
    // hold for 1/4 second
    delay(250);
    // turn it off
    digitalWrite (columnArray[y], HIGH);
   } // go to next column
//turn off row
digitalWrite (rowArray[x], LOW); // turn off cathode
} // go to next row

} // end loop