Don't ever compare yourself to other people, especially in terms of apparent success.
> Some of these terms people use and other stuff has made me doubt myself
Sounds like you want to fill out your knowledge base. That's straightforward enough. Note what you don't know, then research it and try it out in practice. It seems like you're an autodidact and that's fantastic.
> Is there a way for me to learn all the stuff they teach at companies by working in Open Source projects?
No. You can't learn to live in the desert by living in the forest.
> All I need is knowledge and mentorship.
The first is on you. The second is on you too.
Have you looked into the people that work along side you on those Open Source projects? Undobtably some of them have production experience.
Learn to speak buzzwordese.
10X your ego.
/s?