Yes, you can play on a controller at a good level, but I sadly don't know a YouTube channel with some tips.
So I will give you some, as I've known nothing but a controller for racing games. I do recommend that you increase your controller sensitivity to 5 or 6, as that will help you turn faster. As there is less range of movement compared to a wheel, it's important to maximise your input. Don't try to turn the car whilst under brakes or you will struggle to get round a corner, as I've found out many times. Make sure you feed the throttle in rather than just jamming it out of a corner, as you can make some serious gains simply by apply power at the right time. As with the brakes, modulation is critical in ensuring that you enter a corner as steadily as possible. When turning a corner, slowly release the brake instead coming off it instantly.
And yes, wheel users and controller users are mixed together in Sport Mode. But don't let that be a deterrent.