Dragons are mere myths,some claim astral visions of them as well as interactions I,can not speak on such things since I spend my time on the Earth Realms as a Folk Magician,use the right key words and you will find plenty of Drangon lore on this site.
As much as I would love to my knowledge is very limited. They were once in the physical world before a lot of magic was sealed away for its own protection. Therefore there are descendants of dragons that are lizards and they don't have any magic.
They are intelligent and hard to come across even in the astral plane
DJ Conway isn't the best source because she makes stuff up [and I read Dances with Dragons, there was maybe one chapters worth of information. Everything else was pure fluffy nonsense imo anyway] sadly she is credited as the founder of Dragon Magick.
Little is written because A. it's passed verbally from the dragons to you [and again, they are ASTRAL they are not physical] and B. many clans [covens] typically have a code against revealing information to those who haven't been proven trustworthy.
Best to look into astral projection and speaking with them directly. They aren't evil, a little intimidating but if you wish to learn so you can grow on your path they will more than likely teach you.
Couple things though:
You cannot summon a physical Dragon, nor can you control a Dragon. Dragons are seen similar to angels, demons, or fae, you work with them.
You cannot become a Dragon, nor can you gain their powers or grow wings/tail/scales/claws like a Dragon.
Dragons take things seriously as well as literally. Treating things as a joke, or wording something wrong will end badly for you.
Every path is different. They will teach you what you need to know now, so don't argue you want to learn [example] spell casting when they want you to learn about chakras. There's a reason.