I know how to program but I have no clue where to begin with software development. Any advice?

Hi! I'm a college sophomore studying CS and I thought the programming classes I've taken would help me begin working on some app ideas I have but unfortunately I'm stuck on very basic things?

What would be some good resources, books, or even online courses–any thoughts on MIT's 6.031?–for making the jump from programming to software development? I am really willing to put in the work so throw it all at me. From my internship this summer I got some experience with UIUX so I'm also interested in learning more about the aesthetic elements of software development.

Hopefully this post makes sense despite my own personal confusion. It's just disheartening to see that the traditional path I thought would empower me with the ability to build my own stuff isn't proving all so useful. I can see future courses that may help, but I'm itching to start now. Thank you for reading this!