Congrats on your find! I know nothing about Chuckars, but I hope I can offer some help!
You'll definitly want to get at least 1 more Chuckar for your current one. 2 is even better. 2 birds is a pare, 3 birds is a flock. Plus if you loose one for any reason, you wont end up with a lone bird.
The first think your gonna want to do is find some food. I have no idea what you might want to feed since I have never owned Chukars, but usually feed stores such as
TSC carry feed for chickens and ducks. No idea if they will have feed for a Chuckar, but hopefully someone more experienced will pipe in soon.
Have a super large wire dog crate. Should I put newbie in there?
A ire dog crate would work well, but keep in mind that it can take multiple weeks for birds to become accustomed to each other, so something very large like a dog run may be a better option because of the amount of space.
There really isn't anything specific to watch for. At first they will be very curious, and that will wear off eventually. I always wait at least a week, but it can take more time than that. As long as one or the other isn't acting to interested in, or aggressive towards the other through the fence, you should be good as long as they've had time to adjust.
And, do they need heat if it dips near freezing?
Like I said above I know nothing about Chuckars, but I know that other poultry such as chickens and ducks do not. Heat is never necessary unless it gets past -20 degrees. As long as your coop is ventilated correctly, and draft free, heat isn't necessary. Its actually a hazard for the birds and the coop.
Again not sure if this is the same for Chuckars as it is for other poultry.