I posted last week I was having trouble finding baby chicks because my closest TSC were sold out, and hatcheries weren’t shipping until May or later. But!! I found chicks at a different tractor supply near my house! They are all Speckled Sussex and they are the cutest little floofs I’ve ever seen!
Hurray!
I have a lot of questions… what age I can put them in my coop safely
If the coop provides the right conditions for baby chicks, you can put them in the coop as soon as you bring the chicks home.
Correct conditions include:
--protection from weather (snow, rain, hot sun, wind)
--protection from predators (including domestic dogs and cats, wild animals like racoons and foxes, and small creatures like rats and weasels)
--correct temperature (see response to your next question)
--feed & water
do they actually need extra heat in central FL
They need access to a place that is about 95 to 100 degrees Fahrenheit. Not all of their space needs to be that warm, but they need to be able to go into that warm space any time they want. The "warm space" can be provided by a heat lamp, a brooder plate, a broody hen, or anything else that works without causing a fire.
The also need access to a cooler area. It's best if the cool area is 70 degrees or lower (not always possible in a hot climate, but something to at least keep in mind.) It is fine if the cool area gets much colder than that. Down to 32 degrees, there should be no problems. Below that, their water tends to freeze, and they start to have a risk of frostbitten toes as they run around.
Healthy chicks will tend to move around a fair bit: they warm up in the warm area, eat a bit, drink a bit, run off to explore in the cold, run back to the warm spot for a nap, and so on.
A heat lamp has good and bad points.
One of the good points is that the light attracts chicks toward it.
If you use a heat source that does not provide light, consider providing a small light to guide the chicks, or check frequently to tuck them back under if they get cold. They should figure it out within a few days, and won't need help after that.
if I want to bring them inside at night while they still young but big enough to jump on things.. how do I contain them?
Containing them: dog crate, play yard, tent, baby gate, cardboard boxes, laundry baskets, a sheet draped over chairs to make a "wall," the actual walls of a room, whatever else is handy. Maybe covered with something to prevent them jumping out.
Containing their droppings: cover the floor thoroughly, because chicks poop very frequently. They will probably get poop in places it should not be, no matter how careful you are, but you can at least reduce the amount.
Containing their dust and dander: hopeless.
If you only want to bring in one at a time, you can hold it in your hand, or sit it on a towel in your lap.
I may just leave them Outside once they are old enough
I probably would.
If your coop provides what they need, they can live there from the very first day, and not be in your house at all (except for possibly coming in for a brief visit, if that makes you happy.)
but I guess I’m already nervous to do that, because of predators and such. I guess you have to pull off the bandaid eventually

it’s like when a kid goes to school for the first time!!
Yes, predators are definitely a concern. But letting the chicks grow bigger will not make much difference to whether a predator gets them. Most predators are quite happy to eat adult chickens or small chicks. A very few (like rats) are more dangerous to small chicks than to adult chickens.