Will Sore Area Of Glans Penis Be Infected If Foreskin In Not Pulled Back?

I went to see the urologist today about retracting my foreskin, because I had never been able to do it before, and today he retracted it and actually had to manually separate a part of my foreskin from my glans because it had not separated during puberty, leaving that area of my glans red and sore. Also, he never fully explained how to pull back the foreskin. Ive managed to do it on my own, but the problem is that moving it back to its original position over the glans of the penis is difficult. I have to stretch the opening of my foreskin to get it back over the head of my penis. Ive decided to get circumcised and I'm going under the knife on the 16th of November, so about a month from now. My two concerns are #1, since I'm getting circumcised in a month, is it really necessary to exercise and practice pulling back my foreskin? and #2, is it possible that if I don't practice pulling back my foreskin, the sore area of my glans will become infected?