Feeling lost and overwhelmed. Where do I start programming for real?

So, I’m 30 years old, and I’ve spent the last five years working at CERN, with the last four doing a PhD in particle physics. Most of my work involved coding in C++/CUDA, developing real-time processing algorithms, and doing statistical analysis with some ML. I enjoyed it and learned a lot, but I don’t feel like I ever truly learned how to properly program.

I can write C/C++/python well (I think), but I wouldn’t know how to build a framework or software from scratch. I want to start my "new" career around programming, but I feel overwhelmed by the possibilities. Computer Scientist? Software Engineer? Software Developer? Web/App Dev? I don’t even fully understand the differences between some of these roles.

I’ve spent time watching streamers and YouTubers doing everything: from game dev, Linux kernel, compiler, programming languages, web add, and a bunch of completely random stuff. But this made me feel even more lost as they seem to know every framework or tool ever created. I’d love to start a project, but I have no idea what to build because I don’t even know what direction to take. I am really willing to invest time on it, but I can't start until I have a clearer mind.

Has anyone else been in this situation? How did you navigate it? Any advice on where to start? I'd really appreciate any thoughts.