Can you put up some plan with dimensions showing current positions of openings, toilets, etc.

I do bathrooms every day of the week and I can tell you now that, If you really want a bath in that space and shower just do a shower over bath I noticed your shower was 800mm wide this is to small for a shower 900mm minimum. Forget the bifold doors put in a cavity slider or if this is not possible do a face of wall sliding door on the out side of the bathroom. If you really really want separate bath & shower move the toilet into the laundry. Get an 1800mm deep soaker bath and run it along the 2000mm wall run your shower along the 2100mm wall opposite the vanity. I take it your on a timber floor not a slab as moving a toilet on a slab can get costly.

having a broken ankle made me so much more aware of the restrictions on elderley, disabled and temporarily indisposed in most bathrooms so, when planning our new bathrooms we made sure that the doorways were wide enough for wheelchair access, the toilets are installed a little higher to make sitting and standing easier, entry to the shower and access around the toilet are "drive in" The toilets and shower have proper grab rails installed during construction, not as an afterthought, we have straight grab rails installed as towel rails, 30mm square and rectangular textured tiles as a non slip floor, a fold up seat in the shower, a proper chair to sit and dry your toes and help during dressing, controlled temperature hot water, adjustable spray shower heads and hand held adjustable spray (separate to the overhead shower not attached to slip down rails) the vanity and toilets are wall hung for easier cleaning and the space under the vanity is a handy place for a waste bin and slippers out of the way, all medicines are stored in a shallow wall hung medicine cabinet and there's good lighting, overhead heater with fan, underfloor tile heating and all taps are rounded to prevent accidental cuts and bruises on old flesh...the two things to regret are: we installed a walk in hydrotherapy bath that could have waited until really necessary because we have no traditional bath in the house for little kids and we couldn't find a soap dish without sharp edges so that gap is waiting for the new styles to be released...btw all the details about grab rails heights etc are readily available on Google but can't remember which specific sites we used

Before falling in love with some beautiful bathroom photography you really need to take a step back and think about the day-to-day practicalities and your budget. Is this the only bathroom in the house, or is there an ensuite? Is there a separate toilet, or do you need a toilet in the bathroom? Do you have young kids who need to be bathed? Do you need a bath in this room, or is there another one in the house? As an adult do you like to have a long soak in a big bath, or do you always have showers? Do you need bathroom storage for make-up, towels or toilet rolls? The answers to these questions will help you decide on the right fittings for your new bathroom. Many people would prefer to have a larger shower and a smaller bath, but it depends on your household and preferences. The shower over bath is not a good option if you are a regular shower user, but not a regular bath user. It is also quite difficult to bath a toddler safely with a fixed screen in the shower over bath situation. Many people who love the look of the walk in shower with no door, such as in your first photo, end up hating them when they start using them. If not carefully designed and built they can swamp the bathroom everytime the shower is used, so do your research. Your bathroom is also too small to have a freestanding bath (as in the first photo) as you won't have enough room around the back and sides to clean the floor properly. You are better off with a bath built into a bath hob which is in the second photo. Best of luck with your considerations, Dr Retro of Dr Retro House Calls