As for feeding, I advise feeding in a separate cage. Stay away from mealworms, they are impaction nightmares due to their abundant chitin. Dubia roaches- or any kind of feeder roach, some prefer Turkistan Red Runner roaches- are an ideal staple for a young bearded dragon, with crickets being a decent second place. These roaches are easy to keep, and Dubia roaches in particular lack the ability to climb sheer sided plastic and glass enclosures, making keeping them contained a cinch. They are also easier to handle than crickets which jump all over the place, and gut load better (keep your feeders well fed before feeding them to your dragon- anything in them goes into your dragon).
Only feed insects no longer than the width between the eyes. Any larger will block your dragon up and cause an impaction. Even a chance few may cause your dragon some discomfort as it tries to pass them, so if in doubt, don't risk it.
Feed as many insects as your dragon will eat before losing interest in them. If this is a young dragon, that means at least twice a day, and at least one of those feedings will require calcium with D3 applied liberally to the feeder insects. If using roaches, you may need to do this manually, though with crickets you just need to put them in a container with some of the calcium, shake, and serve./
Apologies for giving you the third degree, but it was important to know what your dragon's setup was in order to ensure you missed nothing. Bearded dragons are relatively easy reptiles to keep, but reptiles they are, and their husbandry is more complex than that of birds and mammals.