Hello, good day, I am new here, and also a recent player, I already got my account authenticated and I want to know if there is an index of topics of sort, specially about events and gacha. (google translations are somewhat unreliable to a degree). Thank you in advance! 
Hello and welcome

Some Japanese resources that really helped me in the beginning were on this page:
http://www18.atwiki.jp/imas_cg/pages/240.html#id_6b883ae5For English resources there isn't really much about the events and stuff, I was proposing to form some team that would update the wiki with event articles and add new ones for the event but nobody really replied and I can't do it alone.
I posted few strategies in this topic
Dream Festival (currently running event)Idol Royaleyou can use those and then adapt what you learn to the currently running event, usually the team based events are about getting good share of the points or watching when you can snipe a 3rd place with just few drinks etc
Also if you're going to focus on events, make sure to put EVERYTHING into Stamina, its the most important stat. Only use MY stamina drink, not regular Stamina Drink (those are valuable currency).
Read the FAQ that comes with the event, you can access it from the event's menu in game, but its in Japanese... But it has lot of basic info about how to play the event.
And as for gatcha, you can earn lot of tickets from events and basically check through the gatcha pages and what you can click and doesn't say it requires MobaCoin - click it as you have ticket for it xD Make sure to also do the campaigns like the login on android with the client (just use proxy or vpn do download the client and you can use like Bluestacks android emulator to run it), and all the other campaigns too, you can see the current campaigns above your "STATUS" on the My Studio page (the main page), some of them you like need to link twitter and stuff and you get free stuff so that's definitely worth it.
Oh also if you are not lvl 20 yet and nobody invited you to the game, you can go to the ID campaign (Midori image) and put in my code "BGrbGN" and you will get a gatcha ticket and some stuff and a free 18 cost SR and I will get like a gatcha ticket too.
As for MC gatcha, the least amount of $$ for the most value is getting the 50 coin 1/5 step gatchas but only the 1st step - during the 5 step it resets every day so you can usually get about 10 of those when they run.
Currently that one is called "5STEPガチャ(1STEP目) (ドリーム報酬付)"
It is not always there, actually I'd say there is one like every second gatcha so get those while you can.
Each one of those will give you for 50 coins (so like 50 cents)
- 1 platinum gatcha
- 2 stamina drinks (thats really good)
- 1 extra gatcha or gatcha points or special slot
(extra gatcha is like 3% SR with puchi; points you can use to buy extra plat tickets; special slot you get the chance to roll for some really good stuff, if you're lucky [like some people here but not me! xD] you can get the ultra SR from that, but usually you will get like another gatcha or like 50 event drinks [thats pretty good if you get that] and other things).
That one is just super value compared to some of the 1000 coin ones.
Oh and there is the special Anime gatcha where the first one costs liek 10 coins and gives you some drinks, definitely get that - its basically free drinks (for 10 cents) - I got that up to step 5 and then didn't get that one since it is just guaranteed Rin which I already had as she was so cheap on shop).
But yeah basically even if the 50 coin step 1 was only the 2 stamina drinks, its really worth getting a stam drink for 25cents since usually they cost like a dollar each xD
So yeah, hope this helps and if you need help with anything you can ask here.