if ur new to the make, i suggest mostly practicing and taking other gals ur age as reference dpeendinf on how u want it to turn out! my biggest tips are so make sure the colors (eyeshadow, blush, lip) arent too dark, and that u try to make the liner downturned
So I know little to none about makeup application but I do however know about makeup brands themselves. But first a few questions so I can help you a bit more
What gyaru type of makeup are you trying to achieve?
Are you trying to. buy online or local to you IRL?
I'd say it heavily depends on the substyle. The best tips i can give literally anyone new though:
Don't compare yourself to gals on tiktok or instagram! Use gyaru models and magazines for reference.
The droop is the key factor to it being even considered gyaru makeup, gyaru makeup without a droop is very hard to pull of from my experience, although you can try.
Lashes and contact lenses help SO much!! Especially bottom lashes
Take it slow and don't rush, I'm begging you don't start with the whole thing immediately if you're new to makeup in general!
Never use fandom wiki for resources. Majority of the information on the site is wrong - use japanese resources with a translator and ask experienced gyarus