You don't need to choose the library but there's still the same amount of documentation to wade through, the amount of learning is the same.

although, code separation is native in React now and if you think http clients is still a thing you're too far into the Angular ecosystem to be helped.

Forms: use HTML5 and expand on that. State: quick read, I'd say use context, hooks and effects if you're new. Styles: I despise style in JS, so I go with SCSS or CSS. The encapsulation problem is made up in 90% of all apps. Http: just use fetch. If you'd like, you can write a vanilla wrapper around it. Code separation to modules - don't get what you're going at really. Build functional components. Keep shared logic in services, a POJO wrapping functions and exporting it all.

From my experience, learning React and picking an approach for each of the above is faster than learning Angular.