All the beginner videos I have ever seen were 90% fiction and 10% reality. Even the ones removed from the forum for exactly that reason.
Read the written guides. At least you get some actual information, not the bullshit put together by fetishists from porn clips with no real world experience about canine semen influencing your psychology, providing nutrition, cervical penetration and cumming directly into the uterus, sucking a dog like a human, not holding the knot, knotting actually being possible (humans are not equipped with the musculature required for that, the knot does not get stuck in a human vagina, you actually have to hold it with a hand)... and crap like that.
Learn how to properly jerk/suck a dog off, how the penis works, where are the most sensitive parts and which parts you should not rub (the shaft cough cough) and where you should hold the penis and where you should not hold the dog (legs, tail, collar).