SWEETNESS!! Welcome!! Happy to have you!! I’m so excited that you’re starting your journey as a creative weirdo! <3 <3 <3
Your instincts sound spot on with the concrete and mixed metals. I would definitely stick with aged or dull finishes to the metals because you’re right, the bedspread is loud.
Some advice on that — try using just the comforter, not the pillowcases. Adding dark gray pillowcases instead the patterned ones that came with the set will give your bed a sophisticated, designed, hotel vibe. Then, try plucking out more of the neutral tones from the bedspread to use as accents in the rest of your room. This will all enhance the sophistication of the space.
Good luck! Have fun! And please post pics when you’re done!