This is my first post on Dev.to, I hope it will help you in some way.
Long before I decided to make an npm package, I wanted to get in open source. I tried a couple of times but lost motivation soon after.
I was working on my personal project, and I wanted to create some functionality, but couldn't find an npm package for it. I started building it from scratch. It was fairly simple to build, it took me a day or so.
After some time idea to publish it hit me, but then I realized that what worked for me at the moment might not be good for someone else. I rewrote everything in its own repository and wrote a bunch of unit tests to make sure everything is correct.
Don't force yourself to write open-source software, it will come to you when you are ready. I learned a lot from this little project. And I hope this article inspired you in some way. You can find my npm package here.