Having difficulty in learning layout properties

I’m having difficulty in learning the CSS layout properly. I have made easier websites like portfolio, tribute, Random Quote machine etc easily using bootstrap. But when it comes to using “Vanilla” CSS like use of position properties( fixed, relative etc), stacking multiple elements side by side and changing width without disturbing elements, I just can’t get it right.
Is there any other tutorial (preferably video) that can teach it. I’m currently reading through learnlayout.com .

I think it is mainly through practice that you get to know how some properties work. But there is plenty of resources out there that can help. Css tricks has great explanations of css specific properties.