Walk In Shower...Any Specifics?

I am wanting to change our shower area from a shower bay with the horrid white acrylic base to a walk in shower.

Are there any specific things that have to be changed building/plumbing wise for the drainage?

Do the tiles need to be sloped down or is it just plain straight tiling?

Please forgive my ignorance as I am new to this.

I cant help with all you need to know, but you will need to ensure there is a slope to the centre of your waste

I apologise but your question has very little information to work with and is hard to paint the whole picture of what you are trying to achieve. However I will depict a few different scenarios: For the best result I will make suggestions as if I was doing the job and I am talking with plenty of experience in all aspects of waterproofing and floor and wall tiling as I am licensed in both. Firstly I will assume you are doing a complete reno for which I would bed your entire bathroom floor and install two wastes in the room, ( If not already) one in the shower area and one externally which if there isn't one I would definately suggest putting one in. I would then screed the floor having the area for the shower falling to its waste and the rest of the floor falling slightly to the external waste, making an exception for things like the vanity or toilet if in the same room ( all factors would need consideration and I can only go on what you have posted ) For a timber floor substrate it should be rather easy to achieve everything I just described. A concrete substrate on the other hand should have an external waste already which you will have two options: The first is to still do as previously described and bed the entire floor with fall to the wastes. The other I would look at recessing just the shower area by cutting the slab down 40mm how ever big you want your shower to be, bed that area to the height of the slab again with fall to the shower waste. I would also grind the external floor down to make the fall to the external waste, then when you tile your tiles will all be the same level. ( Grinding the slab to create fall would be the hardest way but you do not end up with a step up at the door) For the best result and fail proof results if done correctly is to bed the entire floor and create your own fall.
hope I have been of some help and good luck.
If you need any other help I would be more than happy to help