as posted early, i'm new to the game. played a bit more today and i was trying to figure out the currencies in the game. have i got this right?
real money buys you genesis crystals which you can use to buy some things but you can convert them to primogems and with them you can buy fates? i'm not sure the difference between the two fates. one is blue and one is blue/pink-ish. starglitter + stardust i don't understand. i have some so i guess you earn them as you play and if you wanted you could use them to buy fates?
there is a beginner's wish. do i need to do that? or do i do the wanderlust invocation one? i don't have a lot of material right now. i could maybe buy some fates but i'm too scared to do anything until i understand it better lol.
as for story, i done a quest finding treasure which turned out to be fake. i have 4 characters now! kaeya and lisa. all lvl 20 and lvl 20 weapons. i'm confused about how artifacts work at the moment.
Don't worry about genesis crystals. You shouldn't spend money on this game.
As you say there's two types of fates. The blue ones are called acquaint fates, and can only be used on the standard banner and the beginner banner. These two banners don't contain anything too noteworthy. Because of this you should never convert your primogems into acquaint fates! Any acquaint fate the game gives you is a nice bonus and should be used.
The rainbow-colored fates are called intertwined fates, and they're used on limited character banners and weapon banners. These banners contain powerful 5 star items that are temporarily available. As such you should hoard all your primogems and spend them on intertwined fates when a character or weapon appears that you want.
Starglitter is a currency you obtain after pulling duplicate 4 and 5 star items on any banner. Starglitter can be used to purchase a multitude of things in the Paimon's bargains shop, but the only ones you should consider are the blackcliff weapons (which appear every other month), 4 star characters (if you really want them) and wishes (intertwined fates are the safest investment).
Stardust on the other hand is given to you when you pull garbage items on a banner. This stardust is really only used to purchase five intertwined and five acquaint fates every month. There's not much else to spend this currency on so it's always worth buying those. Prioritize the intertwined fates.
As for the beginner banner, I think you should only use acquaint fates on it if you want Noelle. Don't use primogems. If you don't care for Noelle, using those blue fates on the standard banner gets you closer to a 5 star item, which is more efficient.
Artifacts are equipment that boost your characters' stats, and most of the late game revolves around optimizing them. Don't worry too much about them early on, and just put some artifacts on characters you use that you think would be useful. You should look into them more when you're more familiar with the game.