The daily routine of an iguana is centered on warming up, getting rid of yesterday's food, getting and eating more food, basking, maybe going to eat some more, basking again, and going back to bed.
To be more specific: as the morning sunlight begins to penetrate the overhead forest canopy, the iguanas begin to move from their night sleeping places to a branch where they can soak up the sun's heat. After a few hours, they are warm enough to defecate and move around and forage for food. After climbing, searching and eating for a couple of hours, they move to a basking site to catch the last of the afternoon heat; they must be warm enough to digest the food they have eaten before they go back to their night sleeping places. While all of this is going on during the day, the iguana also has to be on the lookout for bigger iguanas looking for smaller iguanas to intimidate, and for other animals that consider iguanas to be a tasty addition to their diet. Male iguanas also have to avoid entering (or being caught in) another male iguana's territory.
During breeding season, iguana activity levels increase as male iguanas are looking for females and uninterested females are generally trying to avoid overzealous males. At the same time, younger sexually mature males who have yet to carve out their own territory are trying to grab what they can when they can as often as they can.
The smaller the iguana, the farther down the food chain they are. Young iguanas are near the bottom of the food chain, being eaten by carnivorous and omnivorous reptiles (including snakes and caiman), large amphibians, birds and mammals. In some areas of the green iguana range, "mammals" include humans. This helps explains why your new iguana is terrified of you--he thinks you're a giant predator ready for an iguana snack.
Thus, iguana days are filled with bursts of activity punctuated by long periods of quiet rest. These behavioral patterns occur in captivity, as well, with sexually mature iguanas exhibiting the seasonal variations of their wild cousins. Outside of the breeding season, iguana behavior research has found that wild iguanas spend 90% to 96% of their time doing pretty much nothing.