A 8 week old beardie would be classified as a hatchling or baby. I wouldn't consider a beardie a juvenile till 4-5 months of age.
In my opinion ages go by this,
1-4 months baby/hatchling
4-12 months juvenile
12-24 months sub-adult
24+ months adult.
There is some mixtures in stores that you can buy but the majority of the time they do not have the best food items for a beardie in it such as lettuce and spinach and a few others that can't be used at all or at least not often.
Preferably you want to feed collard greens, turnip greens, endive, mustard greens and few others daily along with their insect meals.
Heres a decently good feeding guide that should help out.
Do note the 10-20 bugs a feeding is a minimum, most do how many bugs they will eat in a 10-15 minute time frame. Personally, I'd recommend doing it this way rather than only 10-20 bugs a feeding.
All life stages eat 10-20 bugs a feeding.
1-4 months 3x a day.
4-12 months 2x a day.
12-20 months once a day.
20+ months twice a week at the least, every other day at the most.
Staple feeders - Crickets, locusts, grasshoppers, silkworms, black soldier fly larvae, dubia roaches, turkish roaches.
Treat feeders - Waxworms, hornworms, superworms, mealworms, butterworms.
Wax worms - once a week, 4-5 max.
Hornworms - every other day to every two days, 4-6 max.
Mealworms - every other day to every two days, 5-10 max. Only for beardies above 6 months.
Superworms - once or twice a week, 3-4 max. Only for beardies above 12 months.
Butterworms - once or twice a week, 3-4 max.
Daily greens- Turnip/collard/mustard greens, endive, and kale if added to a mixture of the other staple greens mentioned.
Fruit once or twice a week - Banana, strawberries, blueberries, blackberries, red raspberries.
For more food items -
http://www.thebeardeddragon.org/bearded-dragon-diet.php
http://www.beautifuldragons.com/Nutrition.html
Supplementation -
You want two supplements at the very least, a calcium and a multivitamin.
I recommend the Repti-cal brand but zoomed is also good.
The supplements should be lightly dusted on all bugs.
Generally, beardies below two years need calcium 5x a week and multivitamins 2x a week.
However, beardies above two years or at two years of age need calcium only 2-4x a week with multivitamins 1-2x a week.
This does depend on how your beardie is with diet, health, just laid eggs, is laying eggs, etc.
