Build a bigger coop than you think, chicks get a lot bigger. Do not get a pre-fab coop. They are darling, but really should only house two - three birds. There are pages of coops on here. I built one, and love it. I prefer a coop that you can walk in.
Some chickens die, some chicks die. It is sad, but a fact of life, do not feel too guilty. I have kept a flock for years, but not the same birds.
If you collect eggs everyday, those eggs are good and safe to eat. Only Americans keep their eggs in the fridge, elsewhere they keep them on the counter without a problem.
Good commercial food, clean water, good dry bedding and enough space with hideouts, roosts, and platforms and you should do just fine.
It is more important to keep chickens DRY than warm after they are 2-3 weeks old. They will keep themselves warm if dry and well fed.
It is a wonderful hobby, with many aspects, start small and see.
Mrs K