What "Software Engineering" infos should I learn to land a Job in a tech company

A bit of background, I decently know Java and Python. I've done game programming using C# in Unity. Because of financial reasons, I can only be self taught

Im really curious to what a software engineer does. Watching some videos, they dont say what they are actually doing, which makes me very confused on what should I do. My main goal right now is to work in a tech company, but the problem is, I dont know what to study.

If I wanted to pursue games, I have a road in mind. Find an engine, learn the language used, then practice by doing personal game projects. However when I think of pursuing as a Software Engineer, which is what i want, I cant think of the road map.

Should I learn a tech stack first? Should I learn how to make Android Apps? Should I learn how to make a website inside out? I am legit in a state of " I dont know what Im supposed to do". To alleviate this feeling, i bought a course in udemy about learning tech stack and making android apps. And im not even sure if what I'm going to study is going to be relevant.

TLDR; What should I learn if I want to pursue the career of Software Engineering in a company say Facebook or Google or something like that. I already know Java Python, C#, and currently looking into Javascript. Im not interested in Web development, but if it's a pre requisite to becoming a Software Engineer, I'll study it.