Build many things. While you are building them, do it however you can make it work (you may learn some things noone else has done). But look up things you get

Build many things. While you are building them, do it however you can make it work (you may learn some things noone else has done). But look up things you get stuck on. Use the things you build. So build things you want to see happen. While you use them, you will make them more reliable and see the pain points. In future projects you will avoid those/have solutions you instinctively go to because you experienced it. Write some libraries along the way to help with the pain points you solved yourself. You will learn what makes a good interface and documentation for 3rd party libs which you will probably be using a lot of, even if it's just the main framework or standard lib of the language you are using. Lastly, all of this will help guide you in your evaluation of new languages, frameworks, and libraries, which you will be doing a lot of during your career when you build/rebuild/extend. Good luck!