I would have 1 grout line in the door way running to the shower.
How to center wall tile.
I have 18 18 tiles.
Cut tiles to fit along the vertical and horizontal edges of the tile wall.
Then scoop a little adhesive on to a notched trowel and spread it onto the wall in a thin layer.
I have a bathroom in the exact layout as you showed above.
Insert tile spacers between the tiles.
Before you can tile a wall remove the existing tiles fill any cracks or holes with spackle and sand the surface so the tiles will have a strong level surface to stick to.
The wider the spacer the wider the grout line between the tiles.
The best way to achieve the best layout work is with carefully drawn layout lines.
For countertop layout begin with counter trim then set full tiles from the first row working back thus all cut tiles will be placed on the back row against wall.
Spacers of 1 8 inch are standard for most projects but you may prefer to leave more space between tiles.
Make straight cuts with a tile cutter.
Shower on the back wall toilet and vanity.
Tile spacers come in a variety of widths.
For wall layout find the center point of the wall using a level to draw a plumb line in the wall s center.
This is an important step in how to tile.
There are many ways to establish a layout but the best way is to use the same method as with floors.
However wall tile installation has its own set of rules that you dare break at your own risk.
Remember to allow for a 1 8 inch expansion on the bottom of bathroom floors.
Or would you start on the left wall notching the tile for door jam.
Would you center a 18 18 tile in the door way and make your way to the shower base.
Establish centered vertical and horizontal layout lines at the very center of the wall then install the tiles beginning at the center and working outward in quadrants.