Don't feel foolish. It's often hard to figure out what the proper care even is. It's great that now that you are learning, you're willing to make the changes! A lot of people decide that their iguana "likes it that way" and refuse to change the care.
Mostly it's a matter of getting your cage, lighting and diet right. These will be the most expensive changes initially, but once they're made, you'll almost always have a happy, healthy ig from then on.
If you have two in the same cage, you'll probably want to plan for two cages and separate them. The reason for this is because iguanas are firmly territorial. They don't like to share, and they'll often bully each other into not eating, or becoming nervous and agitated. Sometimes they will fight. All of this is bad for their health, though.
Each cage needs to be pretty big. 6 foot tall, by 4 feet wide and long is a good place to start. Bigger is always better, though.

Most people choose to build these cages, so they're actually not *that* expensive depending on your materials. But you definitely want something that will hold humidity and will enable your iguana to climb.
After you've got the cages built, you'll need a strong UVB for each, and then heat lamps or a heat source strong enough to maintain high temperatures. You'll have to get a temperature and humidity gauge to help see where you're at. That's all a matter of playing with your set up until you've got the right temperature and humidity - and after that you're just maintaining.
By the way, it's probably the heat rocks that you've heard burn the iguanas. That's completely true and should not be used. The Ceramic heat emitters are bulbs that specifically produce heat and not light. They definitely CAN burn if your iguana touches them, but the should be well out of reach of your iguana.
I think you'll do fine with these iguanas. But you definitely will have to search out a good reptile vet and start the Metabolic Bone Disease treatment. With that and the environmental changes, you'll have a couple of healthy igs for years to come.