Hello,
The main points to cover are as follows:
A quality coop: you get what you pay for. Allow a minimum of 2 to 3 sq feet coop space per bird. Half that for bantams. Allow one nest for every 4 layers although they seem to all lay in one
Feed: layers pellets or mash both similar price but mash is better for non free range systems as it takes longer to digest and decreases the chance of bullying etc. Although pellets do reduce wastage and ultimately rodent activity.
The law: by this i mean are you allowed to keep livestock in your area, especially if you are in an urban area. Ask your neighbours how they would feel about you having chickens, as even the hens can make quite a racket when they lay an egg.
Bedding: you can use straw or shavings in the coop and maybe hay in the nest boxes if it remains dry and airy at all times. If it gets wet it will produce fungal spores which can cause aspergillosis which is a very annoying respiratory disease. Whatever you choose keep it fresh and dry.
The run: allow a minimum of 10 sq feet of run space. Less if they will be free range. Use large woodchips (not bark mulch) or large flake shavings for the floor if its a hardstanding. If not then dry soil will be fine. Theres also some rubber chips on the market although I have no experience with them.
Diseases: the main health issues are worms, coccodiosis, mites and lice to name very few
Below is a great website with lots of posts and everything you need to know and helped me a lot.
https://poultrykeeper.com/general-chickens/beginners-guide-to-keeping-chickens/ Good luck