On this link you'll find lots of information on almost every aspect of keeping birds - from coop building ideas, to incubating eggs - https://www.backyardchickens.com/articles/
There’s a link on the page above to the Learning Centre - it’s a great resource. If you have a specific topic in mind, just type it in the search box - there's a wealth of information on past and present threads.
Bonjour and welcome from France! I hope your chicks recover! Mine lived in the back of a huge old converted TV for a few weeks until about 12 weeks when their coop was finished ! As long as they are safe and dry and clean it is all good!