One of the easiest ways I have found to improve myself is to find someone around your level of skill(or slightly better) and just do games with them over and over to practice timings/build orders etc.
When I want to practice macroing, I usually like to do 4v4s and practice consistently making workers because I struggled with this concept since I was a wc3 player. Another way you can practice your macro is to do what I said above and agree to both do FE(fast expand) builds.
When it comes to learning build orders, copying other peoples build orders exactly never really works IMO, Everyone has a different style of play and u must adjust it to your style. But the basic skeleton of the build order remains.