Hey there
your problem is not with you (except no Kale, and use Romaine sparingly... they get addicted easily and it has zero nutritional value... a life lesson for yourself as well, lettuce is just water...) its with what the iguana's been fed for the first 6 months of its life.
It's going to take some patients and diligence but he'll eat eventually... one thing a healthy ig likes is eating 
Don't be discouraged by the fact that the ig won't eat in front of you... I've had my girl for 8 months, she's approx a year old and she still will not eat in front of me.
Make sure you're offering it to him at the right time of day... usually around 11 am or noonish, they've had a chance to bask and warm up
Make sure the ambient temp in your cage is hot enough
generally around 85-90 in the warm end, and no less than 65 in the cool end... iguana's cannot digest their food without proper heat... he'll need a nice warm basking spot. My girl has a ledge right up close to her light (keep the light outside of the cage though so they can't get onto the hood itself and burn themselves...) so she can soak up the heat when she's done eating.
I noticed the same problem when I first got mine, so I cut the portions down... give him smaller portions and at first making it easier to see if he's eaten anything, and if he is, what's he NOT eating?
some people make the mistake of offering their baby igs way too much food which just ends up going to waste... they're little garbage compactors and can eat a lot, but a heaping cup of food for a baby lizard is a little much...just keep an eye on him, if you notice all of his food is gone, give him more, it's a matter of playing around and observing
If he's still being picky, be persistent, keep offering him different combinations...at first it's going to be frustrating and a little expensive since most of their foods are hard to buy out of season
another thing to keep in mind is stress. He's in a new place, you may have other pets or small kids bombing around bothering him... or there may be something in his cage he doesn't like, maybe something he's lacking... how's the humidity? and is it warm enough?
other than that: Melissa Kaplan's Iguana's for Dummies will have all of the answers you need.
best of luck
if he still won't eat after a few days, call your vet.
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Alexandria Neonakis
Owner of:
Olivia the Female Green Ig
Maize(f) and Onyx(m) the cornsnakes
Peter(m) and Lois(f) the Leopard Geckos