thank you!
Not to age myself, but yes, I got those when I was 12 haha. My dad has an old pioneer setup and his old school tutelage is how I got those. I actually was looking for information on where to go from them, and that’s how I found this website!
General consensus here is that speakers and speaker placement have the biggest impact on sound. Most amplifiers have a pretty flat response so not much of a difference there until you get into different types of room correction in modern receivers and amps.
The VM95ML is a decent cartridge but that is a whole other world when it comes to personal preferences. The phono pre-amp is a personal choice too but phono equalization is such a mature technology that it's hard to find a really bad phono pre-amp. If your AVR has a phono input it likely would do the job fine. The Fluance is a good starter table and should give you years of enjoyment.
Some upgrades are just for fun or aesthetics. Others you may have certain goals in mind. With what you have now, I would try and listen to as many different brands of speakers as you can. Each company has their own design philosophy and they can sound very different. Reviews are a good guide but it eventually comes down to what you prefer. If there are not any audio stores in your area, some members go to the used market to try different brands and then resell them.