LED On/Off code:

#include <avr/io.h>

#define F_CPU 20000000UL
#define LED_PIN PA7 // Define LED_PIN 7 Red LED
#define PUSH_Button PA3 // Define PUSH_Button

int main(void)
{
DDRA = 0b10000000; // Configure LED_PIN (PA7) as output
DDRA = ~(1 << PUSH_Button); // button is input
      
while(1) //infinite loop
   {
	if(PINA & (1<<PA3) == 1) //If switch is pressed
	{
	PORTA |= (1<<PA7); //Turns ON LED
	else
	PORTA &= ~(1<<PA7); //Turns OFF LED
	}
    }
}