Different answers on that one depending on your situation. Is this a first time flock (no other birds in the coop)? Or will you be integrating with others?
Easiest is if it's a first time flock. Be sure your birds are weaned off the heat lamp (I can't imagine in Texas you will have a need for a heat lamp out in the coop. I suggest if the heat allows that you put your birds on lockdown in the coop for 2-3 days to get it firmly in their minds that the coop is now home. If it's too hot to lock them down, well, that's just the breaks. Make sure they have plenty of food, water and a roost (which they may not use at first). Don't worry if they cry, peep, squawk (probably too young for squawking). DON'T bring them back to the garage, it only prolongs the pain.
Do they have a secure run, or are you free ranging? If they have a secure run, after the first couple of days (or if you can't lock them down, then on the first day), just open the POP door and let them go outside at will. They MAY stay in the coop. Don't worry about it. They will come outside when they are comfortable with the situation. I don't freerange, so if (and I'm sure they are) things are different, I can't offer advice.
I don't know much about integrating flocks, so I won't speak to that. Come to think of it, as a first time flocker myself, I don't really know much of anything but what has actually happened/worked for me, and I brooded my chicks in my coop so that made it easier.