changing out the light and faucet is a start, but really, it's not much diff than what's already there you could easily get new hardware. maybe a matte black, or combined black and nickel If you want to modernize, how do you feel about doing a new floor? Painting the vanity? getting a new mirror? That tall, unframed one is just basic. I'd do a diff mirror, hang your new light, and paint your walls. doing a wainscot around the room is one way to bring in some interest. art over the toilet, new mirror Then I'd bring in some shelving or art (or both) over the toilet for some visual interest. do you have an idea of the type of look you want? what you have is nice, but it's builder basic. Doing some wallpaper is a start, but those floors are a little on the country side, so bringing in a modern type of paper may not jive well. you could always paint the vanity white, go w/black hardware, mirrors, and black ceiling (yours is tall so it would look fine). maybe do the shiplap or some other wall treatment.

It's a great look, enjoy your bathroom!

You can get away with doing it any number of ways. I'd probably keep the plumbing fixtures - sink and bath - the same. If it were me, I'd go with brushed nickel for for plumbing fixtures and either a white or thin black frame for mirror - but that doesn't mean you should.

I'm no expert but read a lot on here about mixing metals while I was getting ready for our bath reno. You should have a dominant metal theme such as shower is all brushed nickel and faucets and towel holders brushed nickel. Then you sprinkle in the complimentary metal so it doesn't overpower, like using it for cabinet knobs and mirror or cabinet knobs, lighting, towel hooks. So many ways to add the complimentary metal, such as lotion decanters, shower accessories,, etc. My preference leaned toward using main metal for hardware and other metal for accent items. Have fun!