Oh yeah, the yellow European style butter was a revelation when I found out about it. It tastes way better and is less watery than the pale American butter.
I never heard of filtered milk. Milk is milk for the most part, but once I made the mistake of buying it on clearance. Grabbed it without looking because the price for a normal gallon freaked me out. It wasn’t spoiled, but it was super watery and had a weird color.
The ones that interest you the most will be easiest to stick with. I find things just through my general interests and poking around.
Favorite music genre? Listen to bands from different countries and see how they sound. TV shows, movies, and documentaries from other countries are another big one. Listen to the original language, see if it sounds interesting, maybe read a little about it.
Or maybe you know someone who you’d like to be able to talk with in their language. It could be anything. Pick one or two things to try and you’ll get a feel for what you like.