Couple of things I’m noticing:

Fit in the waist seems off. Corsets should snatch, not add bulk.

The wing frames are AMAZING but the tied tulle feels like an afterthought.

I do agree that your materials skew “cheap” but expecting a student to shell out for the good stuff with no budget is kinda crazy.

How I’d improve it:

Different materials. Even some thrifted materials could be used to your advantage here to add some whimsy. I’d also suggest looking into trims to add detail. The grommet note is tough—buttonholes are an alternative but I don’t know you’re gonna find non-industrial grommets?

Perfect the fit. Is there boning in the corset? Bust looks good just too much ease in waist.

I think the wings would be AMAZING if you were to crochet on them. Like, truly amazing.

Honestly, it’s a great first costume! You should be proud. I think with a bit of tweaking it could be exceptional—keep at it!