Well I have a backyard which I use to practice pitching, I throw at about 30 feet and I am wondering if this was an alright distance to gauge my pitches movement.
Also does it matter that it is flat or would it be better to use a pitching mound

if you want to gauge ur pitches, use a mound and the actual distance you pitch from.

throwing game speed at 30 feet you will get nowhere near the break you will get from 60’6", unless its a really really really good knuckleball