How to transition from studying cs to making something?

I started my computer science major because I genuinely enjoy the subject—not because I was chasing the best job market. Even with today's uncertainty in tech hiring, my passion for building software hasn't changed. I'll be graduating soon, but I still feel like I haven't fulfilled my desire to truly build software. I've created a few small websites and completed academic projects, but nothing beyond the classroom that solves a real problem or reaches real users.

What I keep wondering is: how do young entrepreneurs build startup-worthy software? How do they go from knowing the fundamentals to creating products that thousands—or even millions—of people use? That's the experience I feel I'm still missing, and it's what I want to pursue before I graduate.