One of the my Brocolli plants is already flowering?

I purchased it as a seedling. It was rather large and already starting
to bud. Some later reading on the net led me to believe this plant might
not have been the best seedling since it was already budding. Is this
true? Should I cut back on this flowering bud and await new shoots? Is
this plant still viable for producing food?

Another of the two is similarly budding, but not yet flowering. Anything
I should be doing with it?

Thanks, I'm new at brocolli plants.