Welcome!
First thing to learn is the impact of the room. Avoid small/squarish/uninsulated rooms. Try for a dedicated room with concrete floor. Next size your loudspeakers to the given room, the LS50 are small and struggle to fill a largish room. Next read Floyd Toole's "Sound Reproduction" (either edition) to learn how rooms inherently create huge bass peaks/dips and how to resolve it (multiple subwoofers).
Your system and mine have several aspects in common (varied musical tastes, CD collection, use of a MacBook Air). And of course a huge limiting factor, the budget.
