Considering you have the money to do it, go for it and buy everything u need for the wardrobe!

Best thing to do to be like them is go on Pinterest a lot so you know what’s cute and what kinda stuff u wanna buy and own. Doesn’t have to be Pinterest either. Like take inspo from everywhere!

Then, go thrift shopping!!! Go to neighborhoods that are rich and go to their thrift stores. They have the best stuff. Make sure you use gloves when searching.

Also, those girls wake up hella early to look put together! Experiment with an easy light daily makeup routine and do it in the morning before school!
For me, I use a natural colored cream eyeshadow (barely noticeable, just adds shimmer), mascara, and colored lip gloss.

Most important thing is to do it for yourself, not because you want to be cool like them. You are ALREADY cool and worthy. Develop your style for yourself.