Well given your financial shortfall, I think you should remove it from the cage, discard any bedding, and wash the entire cage with bleach and water. Let it dry completely. Then give your iguana a bath, and gently scrub the wound with warm water and mild soap.
Rinse it all off. Sterilize a sharp scissors by soaking and scrubbing it in 50% bleach solution, get some typical iodine liquid wound care medicine and drench her entire leg with it, then snip the tag of tissue off. After that, keep the entire area covered with a thick layer of antibiotic ointment. I know the ointment is messy, but it protects the wound. You have to gently wipe and reapply it a couple times/day, and watch it very closely. Watch closely, and if the area begins to swell, it's a deep abscess and your iguana is out of luck. She would need to see an exotics vet to dig out the semi-solid pus, get an antibiotic injection and a supply of antibiotics for you to give by mouth. BTW, human antibiotics are generally bad for reptiles. Iguana wounds tale a loooooong time to heal.
An iguana, and for that matter, any tropical reptile is for sure going to cost you a lot of vet money. They are entirely inappropriate pets for people with limited means. You may even have to watch it die slowly in it's cage. If not now, then later. You'll see why if you read this:
This will educate you about the care of Green Iguanas:
All my best,