^ I took a bit of a break during October and November because I got SUPER into Love Live School Idol Festival, but now I'm able to play both (even though I have finals

). You play/ed SIF right? I think you compared the drop rates before to this game and how it was way harder to get higher than an R in that game than it is here.
^^ It's discouraging if you decide to start playing in the middle of the month and you're after the events. If you want to get back into the game for the events, get in during either the end of the month when there's a Score Ranking Event, which is an event that doesn't require bonus pts cards, or at the beginning of the month when it's a Points Gacha+Bingo event, which will help you rack up event cards and they'll be bonus pts cards for the rest of the month, so you'll be prepared for the points related events if you choose to play, or just get nice new SSRs and a bunch of Rs for team building for Score Ranking events.
But, if you want to get back into the game gradually and not mind the events until you decide to, then you can just start playing the game whenever you want in order to play for the sake of daily login fragments and daily quests. Then, when you start playing more songs, that accomplishes your weekly song quests, so you'd still be playing casually and gaining more fragments for every different song you play. Daily logins are 10 fragments, doing all 3 daily quests a day is 60 fragments, and you at least play 2 different songs due to the daily quest so that's an additional 10 fragments (5 fragments per song) from the weekly song quests, so that's a total of 80 fragments a day. Play 4 more different songs a day and you can make it a full starstone worth of fragments per day. You'd be playing 6 games for 1 starstone every day, and that probably will take up max 20~30 minutes.
Then, if you want to do events, just at least do score ranking event, where you'll aim to play all your songs at least once, and that accomplishes all your weekly song quests and at the same time you can see where your team ranks in the event for more fragment rewards (and if you're high enough, event cards/stage costumes!).
Then, if you decide to try to play more, then go for points gacha event for the sake of at least trying to get a copy of the event cards, and also getting lots of rares to help make teams.
Then, you can tackle the points collecting event if you got a few +100% cards from the points gacha event. At least get a copy of the event cards here.
Then, there's also the points ranking event but tbh you can just skip it unless you the event cards are your oshi cause it's just a competition on how much starstones you can use to play more and get more pts and it's hard to compete in that kind of event.
Then, you're back to score ranking lol