You can't blame people for getting upset about what you did. Most folks here put in the time, effort, and research before acquiring their Tegu. They had the knowledge to help their Tegu thrive before they got it home. When people purchase an animal impulsively it's usually because it's "cool" and then the animal suffers from poor husbandry. Here are some answers for you. Search the archives of this forum for more indepth information.
What is the best thing to feed him I know crickets powerded with vitamins but how many should he get?
Crickets are good, as many as he will eat. Also, give him some variety....king mealworms, waxworms, silkworms, fuzzies, SDZ diet
What else should I be giving him food wise?
Answered above
Will he stop eating when he's full?
I've yet to see a Tegu regurge from overeating if provided a hot enough basking spot and it's not handled right after feeding
Do you have to soak the Blue Tegu?
Is soaking recomended?
Soaking isn't necessary if your husbandry is correct. A substrate to burrow in and correct humidity is what he needs for healthy skin and good hydration. Do provide a water bowl for drinking.
Dose he have to have a heat rock? I don't like the like of those things
NO!! Heat rocks are just evil. Give him overhead heat for basking. If you feel he needs supplemental heat at night use a ceramic heat emitter or an undertank heater of some sort.
You will need a larger cage soon. Tanks are not well suited for Tegus. A simple wooden box, waterproofed, with a solid top, will suit a Tegu well. Give him a good amount (10 inches or more) of substrate to burrow in.