The neck bridges are the hardest thing to do. I’ve tried to do them and I just end up hurting myself. I use one of those plate loaded neck developers instead like the ones football players use.
I got a hang of the neck bridges pretty quickly, my advice is to have your coach look at you the whole time and give you pointers. Doing it alone, not a good idea.
This is just a warm up, the training didn't start yet. Do you know they are about to get mentally and physically tested. They can't put everything out in 50 mnt warm up.