Here’s how I started and still learn.
Put this code below in a notepad and save it as test.html
< !DOCTYPE html>
Find some websites with 1column, 2 column, 3column basic layouts and put that css layout between the style tags. Or even start creating your own basic layout.
Then start writing some html between body tags and and then style it.
U can start with basic sized divs (boxes) with gray background color and start learning with those boxes like: positioning, floating, display, margins, padding etc. and see how it all behaves.
Than you can move on to lists, pseudo elements and so and so.
During learning there’s no reason to separate css from html page so you don’t have to jump back and forth between 2 documents.
If you have your monitor wide enough you can have the notepad document on one half of your monitor and browser on the other half. Than, every time you make some changes in notepad, save it and refresh browser and you’ll see the results in real time.
It’s all about practice, practice practice.
Can be frustrating at times but it’s lot of fun.