I'm a newbie at this whole chicken raising thing, any tips and/or suggestions highly appreciated!!

We got three adorable chicks (we haven't the slightest clue what gender or breed they are) about 2 and a half weeks ago, and they were already approximately 1 week old. We live in Israel, so the climate there is quite hot, and we unfortunately lost the littlest and seemingly weakest one last week due to dehydration and we were very saddened...we ever since have done our utmost and avoided such a thing from happening again with our other two (who we managed to force to drink and we saved, phew!). We built a coop, although not that big, last week. Ever since, the other two chicks are much happier that they have room to jump around and play, and they're no longer limited to their low ceiling cage we brought them home with. We want the best for them and to raise them so that they should develop safely and healthily. We'd appreciate any tips and/or suggestions with stages of feed, how much is too annoying for them to be held (the kids really wanna hold them a lot!), how to protect them from the many stray cats in Israel (we already saw one come in the yard, luckily we went outside exactly when it arrived so we managed to chase it out), upkeep of their hygiene etc, and anything else someone might have to suggest for a newbie, all greatly appreciated. Nice meeting you all!

 

Thanks all for the welcomes and the great advice! I'd actually like to request some more advice, actually quite urgent. I now have to chicks, and one seems to be quite sleepy today. It isn't behaving as active as usual and shows signs of dehydration-slight panting, closing eyes (although walks when it needs to) and we are forcing some water through a medicine dropper ever here and there. It actually had gotten cooler today than it was last week around here, but it still seems to have gotten effected by the heat. It wasn't kept under the son, there's a cover to keep them shady. This chick isn't eating that much either, we tried helping it, but it just doesn't seem to get stronger. Although it doesn't seem to be getting worse, it's still concerning me. It also has diarrhea the last several times, and the last time had nothing but water (could we be perhaps giving it too much water, if there is such a thing??) because it's not eating...what's my next best step? Thanks to all for participation!

 

Thanks all for the help, as of now it seems to be feeling better, thank G-d. It started having more regular poop and it started eating here and there by itself. We hope it'll start getting stronger. Hang in there lil guy!
I'd also like to ask what the community feels about the "flooring" of the coop. Most suggest wood chips and the like, but we happen to have put them on some synthetic grass which we just find is more comfy for them and at the same time can be easily swept up from all the dirt abt once or twice a week. Anything wrong abt it i may not be aware of?