Hi, this should be posted in design dilemma.

Ideally you would want 900-1000mm clear space in front of your vanity and for walkways, unfortunately we don't live in an ideal world and have to work with what we have. 700mm would be the absolute minimum width for a walkway to still allow reasonable passage, although I would be reluctant to go this tight. A floating vanity will help the space look larger and storage can be included in a mirrored shaving cabinet or mirror with shallow shelf above the vanity.

Some vanities idea made by me, Porcelain_Artist

En-suite layout is fine, Looks like you have a double hung window with a slightly lower sill to the vanity height. . I’d put a stool in front next to shower screen. Update vanity and top and splash back, maybe lowering mirror. Could put a niche in the side wall if want extra storage. Could change mirror to a cabinet, even if it protrudes, mine does, A smaller basin would increase spaciousness and bench space. Can also increase depth of vanity, to 550. Replace floor tiles if you want but I’d leave shower if you want to keep costs down. otherwise retile to full wall height will improve look. Could add a pendant light over left side of vanity