With Loona the best advice would be to just get to know the girls and the music, check out some Loona TV and varieties.
DO NOT concern yourself with trying to understand the lore and Loonaverse just yet, it will somewhat come to you in bits and pieces but isn't necessary lol.
I mean the overarching storyline can be explained in some videos but no need to go into details lol.
I am kinda a variety addict and have watched some of them already(idol room fact in star and some others.) the only groups i do not watch i killed like say bp twice everglow itzy ect . It is just musically i was never wowed.
I fundamentally hate the debut solo trickle out members concept.
Not as bad as the in house/company sponsored reality competition shows (as those groups are now doa) but close for the content reasons i spoke of. I have zero interest in getting interested with a debuted girl and then more and more come and now poof they are a group.
It kinda works as rookies are rolled out quickly but it also really hurts too.
Say for example purple kiss , the new Mystic group and what ever Kim Nayoung ends up in. I like a girl in each now as rookies but dragging it out over a year and change where ya have to pay attention each month is too much. show me the group see if they work and ill choose.