Thats quite alot to go over! The short of it is there are basic standards discus shows adhere to in their judging.. and there are various classes of fish... solids.. wilds, spotted, striated, open class are examples but not the only ones. Each show is a little different.
I would suggest you have a look at the NADA section of the forum..
https://forum.simplydiscus.com/forum...ciation-(NADA)
They are unaffiliated with SimplyDiscus but we have a long history and they used the forum to reach hobbyists before facebook.
They are the ones that do the discus shows in the USA...not sure how active they currently are. There are shows all over the world and groups like NADA out there organizing them.
Al