Hello and welcome Sam :wave:
My best advice is to read everything you can get your hands on. Care sheets, forum posts, beardie manuals....etc. I know some books have conflicting info, but most people here can answer questions when that happens.
My other best advice is not to listen to most everything a pet store tells you. They are usually wrong and often keep their reptiles in sub-par conditions.
Here's a link someone sent me when I first started posting. I still refer to it often. It has lots of good info about beardie nutrition:
http://www.beautifuldragons.503xtreme.com/Nutrition.html
Usually it helps when you post questions to give us as much info as possible about your setup....temps, size of tank, type of substrate, type of lighting, food - kinds and amounts, etc.