Yes iguanas can be chilled but no matter how chilled they are during mating season it's an all other ball game.
Those are not beginner lizards (this comes from someone who used to do iguana rescue and who owned a pretty chilled rescue iguana)
They are the number 1 disposable reptiles you buy them cheap thinking they are cute and will be puppy tame and than realize that the reality of it is somewhat different. Iguanas are such a problem, most rescues refuse to take them (and this is nothing new)
Coming with everything based on my experience means very little, many people do not provide the proper husbandry that those animals need.
Do it comes with a 6 x 4 x 6 enclosure or bigger? If not this will be one of your first cost, an adequate enclosure.
Does it comes with proper UV light and basking lights?
Do you have the time and resources to dedicate to such animal.
Remember because something is cheap or free does not mean it's something you should get into, do your research, iguana ownership can be very rewarding but not everyone is meant to be an iguana owner.