You know that Beardies are omnivores yes? Its important that they have a supply of fresh veggies in their tank too.
Also, make sure you have the correct lighting, this is very important for reptiles, it can cause health issues if you provide no lighting or the wrong type. Its confusing because there are a wide range of bulb options on the market, some of which are appropriate for certain species, but not others. It would be best to do some specific reading on Dragon lighting requirements.
Its also recommended that you supplement with vitamins- you can get reptile dust at the pet store that you simply sprinkle over the crickets before feeding. The easiest way is to put the crickets in a bag, add dust, and shake- only a little is needed, and dust isn't really good for crickets, so dust only right before feeding, and only as many crickets as will be consumed.
It doesn't sounds like you have one- but heat rocks are generally not recommended, they can burn your reptile. Heat lamps or reptile specific under-tank heat pads are safer, and only over one part of the tank, so that the dragon and move to a cooler section if he feels too hot.
Finally- have fun with your dragon! They are actually quite smart. They'll benefit from some enrichment- changes in their environment, different textures, food placement to encourage movement etc. Sometimes people forget how boring it must be to live in a tank 24/7. I find even traditionally "boring" cage pets are more active and engaged when you make an effort to keep them stimulated and engaged.
