Its fine for them to eat calcium, i actually offer it in all my beardies tanks if they want it, usually in a small bowl on the cool end. (as long as its not calcium sand or they will die of impaction)
https://www.beardeddragon.org/useruploads/#list you can go there and upload pics, come back and hit XIMG to select it when posting.
It would be helpful to see how the setup is just in case anything is wrong.
And yes mealworms are not ideal, especially for smaller beardies (less than 4 or 6 months).
You can offer around 5-10 of those every other day or so as treats or every two days once older, and only live as the dried ones would be even less beneficial. This goes for all bugs.
Staple feeders would be dubia roaches, turkish roaches, silkworms, calciworms/pheonix worms/nutrigrubs/black soldier fly larvae (they have a lot of names, and crickets.
Depending on his age (my guess is he's less than 4 months) he'll be needing to eat 3 times a day, 10-20 bugs each feeding, with at least one feeding having supplements on them.
Calcium 5 times a week dusted on bugs, and multivitamins twice a week.