I started in 2017 and was lucky enough to work for a company that was willing to invest in me learning. They gave me time to learn, and during that process gave me tasks related to building UI elements. Since I had experience with iOS development and web development, building layout came easy for me during that period.

Advice I want to give is make a lot of games. But focus on polish. It is better to complete 5 small, but polished games, instead of 10 unfinished projects. And do make them full, with complete UI, Tutorial, possibly leaderboard and/or whatever the game needs to be completed. Make builds and give it to players to try. Not family and friends, because they will be supportive no matter what, random people. With enough players, you will get feedback - which will improve your skills.

 I did release like 3 games, before I felt confident enough as a game developer, and man it was scary. And technically those games we not build the right way, but it is a learning journey. I then released a game that technically was OK, but still had bad practices. It was at that moment I started doing courses(from start to finish) that included things that were not directly related to my work. That was the moment that everything clicked together. I started exploring everything Unity had to offer as advice. They wrote a lot of e-books on best practices, which are golden.

Now I have invested years into one project, but only after I did release a couple of games. And I can see what I learned in those years, when I refactor code that was written two years ago. That is my final advice, do refactor your code when you find it difficult to maintain. And continue learning. Good luck! I hope that was useful.