Find a professional interior designer in your town. Don’t stalk them—just send a polite email. Say, “I’m starting out without a degree, and I admire your work. Could I buy you coffee for 15 minutes?”
Most designers are actually lovely humans who remember struggling at the start. They might let you shadow them on a project or help them with the boring stuff (calling vendors, organizing fabric samples).
This is called an internship, but you get to call it “adult field trip.” You’ll learn more in one afternoon with them than in a semester of textbooks.