At night you turn off the basking lamps, right? It's good that he goes down, because it gives him some exercise.
I think few people believe in my way of spot heating. But it works and it was safe during my fifteen years that I kept and rescued iguanas.
You just get a cord with a light socket at the end. Lower it down inside the cage until you get the right amount of heat in the right zone. Your ig can't grab hold of it and burn himself. If he tries to jump to get closer, he'll tap the bulb and it will swing away from him. It's a lot easier to do it this way because I'm guessing that the cage is too small to fit a bulb with a hood. There are cheap aluminum hoods that iguanas can't get a toe-hold on, too.
If an ig does climb up on it's heat source, it will lay on the too-warm surface without knowing anything is going wrong. I made that mistake once at the beginning of my iguana keeping. Huge scab, burnt spot on his stomach, took 8 months to heal, and finally he pulled through and lived. Lots of vet money.
Your ig won't really like the blue bulb. It will stress him. They do best when it's truly dark at night. You'll soon need to change the general heat source to a Ceramic Heat Emitter. Google that.
You'll need a bigger cage because your ig needs two temperature choices, one at each end of his habitat. That way his body can dictate which temperature it needs to be at, by moving toward the cool end, or moving toward the hot end, All day long. This is a must. He's a highly specialized tropical obligate leaf-eater. He does not know how to eat dry grass. He uses temperature choice to keep his hindgut flora alive, which digest his fiber into carbohydrates for him. It works in a similar way with cows.
Your ig needs a much bigger cage, even though he's only small. It's because you have to set up those two heat zones.
The wire mesh lets heat escape, making it almost impossible to keep stable temperatures. It will also end up pulling out his toe-nails. We've seen so much of that over the years.
Iguana habitats need to be made of solid surfaces like wood and Plexiglas. Your iguana was cheap, but that's because everything else about him is very expensive.
There is so much more that your ig needs. Do read up on iguana care and do your best to meet his needs.
Do you realize that before your ig has lived half it's life, you will have to abandon him to go to college? Few baby ig buyers know how long they really can live if well cared-for.
Stay in touch, please.