Hi there! Congrats on your new beardie
Unfortunately a lot of pet stores don't know very much about bearded dragons and feeding, I would recommend 20-40 crickets per feeding as bearded dragons do eat a lot more than 5 a day. As many as he can/wants to eat in about 10 minutes is ideal. My lil 3 month old eats a whopping 50-80 crickets a day (2-3 feedings)
Good job getting some leafy things into him!
Definitely make sure you get the right UV lighting for him, as pet store bulbs can be VERY dangerous. A reptisun 10.0 T5 tube light is a good and relatively inexpensive Option
And Red and purple lights are not good for beardies either as they can see those wavelengths of light.
I'm not sure what your setup is but the forum here is a great place to find out how to set that up correctly! I'll just make some key points here
Make sure you have a big enough tank for the temperature gradient he needs (90-100 basking, 80-85 cool end)
No dangerous loose substrates like calcisand or crushed walnuts, good ol paper towels are great, or if you're spending, repticarpet.
