A bathroom renovation should start with the fixtures. Choose a shower, tub, toilet and sink that suits your style and gives you all the functionality you need. Will a standup shower suffice, or does space allow for a tub & shower combination? You needn't match the sink exactly but you'll want some cohesion. Pedestals, round and square designs can all work wonderfully well. Flooring choices are plentiful in tile, SPC, vinyl and laminate. just make sure it's water- and mould-resistant.
If your bathroom is only in need of a refresh, start with the cabinets and vanity (or at least the vanity top). Next, consider new faucets all round for the tub, shower and sink, and choose a lighting scheme that pulls everything together. Final touches can include new towel bars, shower curtain, bath mat and linens.