If I could own and train a dragon I totally would. They are such a legendary creature.
That would be super cool, but also a tad scary!  I wonder where the dragon origination story began
Well the two most popular dragon traditions evolved separate, but they both influenced each other. 
What are they?  What culture did they come from?
It is unknown where exactly it comes from. But the fire-spewing reptile features in many myths around the world. Crossing all cultures and borders.
So the story is similar across cultures?  That's really cool.  What other characteristics can dragons have?
Typically in the myths Dragons are scaled creatures that can spew fire, of course. Some are reptilian some have flying abilities.
What is the earliest historic context where a dragon was involved?