This is such a good question.
Every cloth nappy makes a difference, you don’t have to cloth full time or even every day. You can start as small or as big as you like.
If you are wanting to cloth full time and wash every other day 20 cloth nappies is a good number to start with. I recommend starting with a diverse range of brands and type of nappy, or even try a nappy library, so you can learn what works for you.
Reusable wipes are also easy to switch to as they simply go in the nappy wash with your nappies!
For weaned babies I would recommend fleece or disposable liners, whilst disposable liners still contribute to landfill, they contribute a lot less than disposable nappies.. so if they are what help you make the switch to cloth then go for it! Before weaning the poo can just go in the washing machine, but after weaning it has to be removed as it is not water soluble.