Use Invoke rather than InvokeRepeating. check Invoke function here
public class scriptFlashingPressStart : MonoBehaviour
{
public GameObject off_Logo;
public float dead_logo = 1.5f;
bool pressed = false;
void OffLogo()
{
//do anything(delete or invisible)
off_Logo.SetActive(false);
pressed = false;
}
//use Invoke rather than InvokeRepeating
void press_start()
{
if(!pressed)
{
pressed = true;
Invoke("OffLogo", dead_logo);
}
else
{
Debug.Log("Button already pressed");
}
}
}