billy bow legs

Hello to all, I have a question, or should I say many questions regarding the care of a pediatric pt with a tracheostomy. I have read my nursing textbooks, and online articles, but still quite confused. My book stated that the trachea tube consists of two parts, the outer tube, and the obturator. Am I to understand that not all tubes have an inner cannula? What exactly does a trach change consist of? Is the whole thing removed, leaving an empty stoma(how often/where is this performed/by who?) How do you suction a trach? Do you have to remove any pieces to suction? Does every trach have a cap/artificial nose(and when are they to be removed, besides to bvm a pt)? If a pt accidenty decannulates themselves, what comes in the trach boxes at the bedside, is it the outer cannula(is the outer cannula the piece with the flanges for the ribbons), the inner cannula, and the obturator(which I know is removed) I would greatly appreciate a very detailed answer. Thank you so much.