What are the most important skill I learned from my first developer job?

I'm a college dropout. Was studying computer science but figured that I didn't learn enough at the college for its price. I got an opportunity to work as Web Developer for next year but I'm pretty nervous because I'm still not decent at programming. I know decent HTML CSS SASS & little Javascript. But there are so many other things that idk... I'm self teaching Node JS & Javascript frameworks like express js & such but I feel like I'm learning slow. On top of that, I work 66hrs/week at a restaurant, so... it's a struggle. I'd like to learn more quickly & move up to your level !!

I've coded for almost 1 year and a half at a company has a junior dev and then I got a big offer from a company from a big city, I still can't believe that, and I'm feeling the same emoctions and thoughts that you asked, like am I competent enough for the position? What if I fail? I agree completely when you say that the most important thing is to learn to solve problems, I believe I've really learned that too in my previous job, I hope I'll be able to show my skills and competence, that the company like my work and also to be kind with myself in understanding that now the most important thing to do is to learn their system and have patience

The fundamentals pretty much stay the same when moving from one programming language to another. If you get the basics and fundamentals down, you're pretty much set to learn any other languages "quickly". Of course each language have their quirks, like in JavaScript you have to be wary of variable scopes (which I'm still getting used to); but overall, if you know the basics, you can pick up a language/technology much quicker, which allows you to focus more on learning the things that that language/technology brings to the table.