thank you for reaching out to us with your concerns. Writing code is always difficult, and requires experience. The only way to become better is by training it.
You say, you are a junior dev. You say that your concern is that your code is not good and that you have deficits. That's ok. It's the same for all of us. I often feel that my code is inferior, especially when working with Rust, a language which I still am a newby at. The important part is that you are prepared to receive review and have the drive to improve. And that's the most important thing and what others will respect about you. If you are eager to improve, people will want to help you do so.
Opensourcing code will not magically get people to review your code, but it will at least enable others to actually do so. You could opensource one of your smaller plugins, which you feel confident about, on GitLab or GitHub, and then ask in dev-communties (like Hashnode) for reviews of the code. Ask the community nicely to state their opinion of the style, where they see problems and ways to improve the code. For a small code base, people will likely help you and leave comments, and those comments will show you how to improve. You do not have to opensource everything at once. Gradually learn by what your peers have to say :)
Especially Hashnode already has a record of review-questions, however often just asking for ways to improve a code snippet. Using Hashnode search you can verify that the community comes up with interesting solutions and positive answers to such review questions and sometimes even discussions arise which help other people, too. Check out the following discussions for reference: