500 crickets wouldn't last, they will get too big by the time you feed them, crickets grow fast.
You need to buy the smaller crickets, no bigger than the space between your little ones eyes. He will eat a lot of them. Buying online will save you lots of money vs. buying at the petstore. My baby could eat 100 per day sometimes. You should offer crickets to him three times per day at this young age, all he can eat in 10-15 minutes. Don't leave them in the tank overnight. They will hurt your baby.
Housing the crickets is easy, get a 10 gallon or a tall rubbermaid container. Then get empty egg cartons and paper towel rolls for them hide under and get (or make) cricket food and give them a water source (like cut up fresh veggies (easy to use since your Beardie requires veggies so you usually already have them on hand), water pillows, cricket water, etc. nothing too deep or they drown).
I bought 1,000 small crickets at a time, as he ate so many, they didn't last very long, which was good, as they grew fast. Yes, baby Beardies are expensive to feed, but it does get better as they get older. At one point my baby Beardie cost as much to feed as my full grown large male dog.
Keep in mind this stage only lasts awhile, they grow so fast.
You can also try silkworms. They are a wonderful feeder insect too. You can leave them in the tank and let him eat them as he pleases. They come in really small sizes and since they are soft bodied it is okay if they grow b/c you guy can eat them larger than the space between his eyes and be safe.
Make sure you are dusting the feeders with a supplement. Check out the caresheets on this site. They will tell you what brands to use and also a lot of other helpful information on how to raise your Beardie.
You can try breeding your own crickets to save you money too. But if you only have one reptile, breeding/feeding crickets might not be worth the trouble or money.
Congrats on the new addition