Questions&rants ig..

Halooo, I hope I'm not being a nuisance to anyone 😅 I just have a few questions and a rant ahead..

1. Why is it not advisable to put credits while a song is playing?
2. What does an usage chart mean?
3. What is a dan?
4. What is 15s?
5. What does a ticket do at the start of the game?
6. How does the little note above the screen works? (Like to know if the player is available for playing duo or wanting to play alone)

-Anybody can give me tips when playing maimai(I'm desperate..) I'm always shy and always felt like I'm pressured while playing. I don't even edit my name or change my picture in maimai as I can be a bit of a bother for the other players waiting. -At the start of the game(wherein they allow us to choose any icon at the bottom) I don't understand what it meanss so I just select someone randomly.. -I don't even know where are my tasks located at I'M SHY TO EVEN CHECK IT OR WHILE READING SOMETHING, I CAN FEEL THE PLAYERS BEHIND ME STARING AND I KEPT OVERTHINKING LIKE WHAT IF I'M TAKING TOO LONG ARGHHH) -Yes I'm a newbie.. I was really shocked when the maimai in our mall upgraded, I stopped playing at some point and recently just started again when there are a few players in the queue, even brought me my own maimai card to save progress.. -Can someone also help me in my settings, I'm too scared to even change it(I'm really gonna die out of embarrassment)

Also storytime: The player in front me was listing names to a GC of their community(i guess) of the players who'll be playing next, and yes I had my name on the list(solo) when it was my turn, a cousin of mine wanted to play too so I put another credit but the player was suddenly frustrated while I was inserting the coins to the machine. A player approached me and tried to explain but I couldn't hear them well so I just nodded, I was sweating really hard, I thought like "did I upset them? But why? I only put credit and since I was playing solo why not include my cousin) I hope y'all can help point out my mistakes 🙏

PS: THANKS TO ALL OF U🙏 n plz excuse my english🥀💔