take on progressively more ambitious projects! bonus points if you switch between languages for them. the biggest thing is make sure the projects are things that interest you. I did a lot of work on making programming languages and game solver ai (old school meaning) shit when i was starting out.

Game Dev can also be great because the skill floor of programming knowledge you need is relatively low and you get to have a fun product. You can also viscerally feel the code when you iterate on the player controller which is really cool