Just starting css wish me luck

Good luck

Welcome to hell

luck intensifies 📈

go straight to Less or Sass...make life easier for yourself :)

Hope you're not the one 🥲

Have to say, I don't think plain CSS is that hard and it's easier than SASS and other preprocessors that build on top of the plain CSS in what, for me, just adds complication. I'd start by having a simple html doc open that brings in a style sheet, then get used to adding styles to elements with an ID and some elements with a class. Observe how specificity and the order in which styles appear in the CSS affect the result. Remember you must refresh the browser, bypassing any caching, to see the effect of the changes you make. Look at the ease with which you can add more than class to an element -e.g. .box400pxWide .hasBlueBackground .hasRedBorder etc.
Some people say to avoid adding !important to styles, but I personally think that it really helps at times. For example, I definitely want to see red text if I add the .redText class to an element, so I make the color: red !important.
Group classes together in a logical way and you'll be fine. With flexBox get the boxes working first.

Run. While you still can.

Good luck - and remember to look at it all as a whole instead of the one element you're trying to change. I highly recommend Sass, but only after you've got the basics down

Thank you all for you support