Sound piracy, ripping music off YouTube is a total no-no, especially for those who want to live by standards. As a working DJ, you should follow the code of conduct or in simple terms the ethics of music. Buy music from good sources, as this will not only save valuable time but there will be fewer chances of files being corrupt or not being read by DJ gears. Your audience will pick up on the distorted sound, especially in clubs with high-quality sound systems. YouTube should only be your guide to finding a true gem of a song and a guideline to taking the step to find that track at a more than decent quality.
If something is worth doing then it’s worth doing properly. Don’t cut corners. There’s no substitute for hard work. You should apply the maximum amount of effort into everything you do regardless of the size of the audience or pay packet. Whether you’re playing to an audience of 10 or 10,000, doing something for free or getting paid handsomely, it should all be treated equally. You never know who is watching or listening and therefore what new opportunities might arise from the job in hand.