Iguana's aren't an easy lizard so unless you have experiance you may be getting over your head, I had one before and gave up 1/2 a room to it for years. Even the tame ones will claw you up a lot when they try to climb up you if you're not wareing long sleeves. Make sure you are able to keep adiquite humidity, that was always my most difficult part. Rehomeing a rescue seems like a noble cause but be sure you're able to give it the care and space it needs before trying.