Context is key. Show pics of your space and the floor plan with dimensions.

It is hard to give useful flooring or wall suggestions without seeing the shower, vanity, toilet location and room dimensions.

If you can add photos from the doorway and from the vanity side, plus the room size, people will be able to give much better advice. For now, I would choose flooring and wall finishes by working backward from the new shower: keep the floor slip-resistant, make sure the tones relate to the shower tile, and avoid adding a busy wall treatment unless the vanity and mirror area are going to stay simple.

The shower is already the major fixed element, so the next decisions should help the room feel coordinated rather than starting a second design story.