Seven years ago, I bought my daughter a bearded dragon for her birthday. Lizzie (a boy) was the most docile beardie ever and served as my Etsy model for the first year. He was a good boy even though we didn't know much of what we were doing. He was on sand for the first year and didn't eat high calcium greens.
I remember the first time Lizzie's beard turned black. My daughter panicked, I panicked, and my husband looked online and told us Lizzie was either scared or hormonal (and not dying). Phew!
Now I have a house of black bearding beardies. It's hormone season and all the boys are crazy all day, bobbing & black bearding. Dr Folland says beardies release pheromones and can smell each other. No kidding! I bet my house smells like crazy boy beardies!
Black bearding is mostly used to show off or intimidate other lizards. It can also be a sign of fear or surprise (like if a bird flies overhead). Or it can also be seen on a really sick beardie.
Anyways, what once took me by surprise and troubled me is now so normal it doesn't even phase me.
So start where you're at and begin learning. I am STILL learning things about bearded dragons! Like the pheromones thing.