HTML | CSS | Grid Layout

Even that I do understand basic concepts of flex and grid layout I find my self often having troubles spacing different component as shown on design. After sometime of trying different things I get the challenge done but my code gets more messy with every other line. Any suggestion how should I approuch my next challenge to make it slightly easier and improve my code readibility? I just want to point out that I am trying to finish those newbie challenges using only html and css and not go into frameworks just so I can get a good undestanding of basics.