This is hilarious and depressing at the same time since, having turned 40 recently, I still hope to start a first career in software development in the near future.
My secret is to learn and know "enough" about every OS, every language, every framework out there. Of course you're starting and you don't have either the time or experience to do everything, but do it anyway, slowly, one task at a time. Compare, study a bit, read, and have fun. Also, don't be scared, no one knows everything, you just need to know enough to be able to help (and learn at the same time).
You may need to kick open a few doors. I probably could have done that, but I couldn't be arsed.