Graphic Design + UI resources

Does anyone have any go to graphic design resources? Whether that’s a book blog YouTube channel whatever. I’m interested in making my personal and professional work look less like a developer built it.

I’d prefer it if most of my stuff looked like app.starbucks.com. But I’m looking to learn more about principles of design like spacing and color. I always feel like I’m running uphill when choosing basic things like a background color.