Should i or should i not?

All these while i'm a tee shirt, jeans, converse kind of gal. I want something more mature but yet casual. Something simple but nice. Quite hard to explain so just let me show you la k?

These are simple and nice. Long story short, i just want to look more mature yet simple la. I'm kinda like those converse/ Gap look but yet i also wanna mix it with simple, nice and mature kind of dressing. If you have any great ideas, pls do tell me k?

I just wanna know where to start and where to get affordable and good things that i can always mix and match. :)

See ya.