I'm a front-end developer who studied graphic design. A very important part of UX is app flow and navigating users through your interface in a seamless, graceful way.
When I was studying UI/UX something that helped me a lot was reading Google Material guidelines. Even if you're not using a Material UI library (like @angular/material), the guideline thoroughly explains what a good UI/UX should feel like, look like, and work.
Some links: - https://material.io/design/ - https://www.usability.gov/about-us/index.html (this is more for government websites, but still a good source of information) - https://medium.com/@fluidui (FluidUI is an online tool for creating user stories and design prototypes, in their Medium blog they have a vast list of resources and detailed information. - https://theblog.adobe.com/4-golden-rules-ui-design/ (very good read)
Hope this helps.
Cheers.