Hi Carol - I'm around your age and one thing I've noticed is that life is full of shifts that feel awkward for a while. Like shifting from one's college style to professional, or losing / gaining weight. Things get thrown apart and then settle back down eventually.
I think my current style is defined, distinctive, feels like me. But 20 years ago I'm not sure I could have imagined that. In high school I was an outcast albeit with interesting clothes (the grunge era was kind to me). In college I happily wore men's jeans and tshirts. It wasn't a bad look but very different from what I wear these days. The first big awkward transition was college to grad school (2002). My grad school roommate basically staged an intervention. She got me some modern jeans (fitted, boot cut, not men's) and I finally started wearing a bra!
Anyway, I just kept on shopping at consignment stores and honing my style, with more hits and fewer misses over time. For the past 5-10 years I've felt really comfortable in my wardrobe. There was no one moment when I felt like I'd 'made it' though. (To be honest, having a bit more money helped...)
I developed my style by analyzing other people's clothes and browsing shops. Your path might be different - maybe your art student style is intuitive and you'll refine it with nicer items and more editing. Maybe you'll go back to the freewheeling student look with no problem. But in any case, it can be a lot of fun!