PLEASE HELP WITH PUMPKINS & BROCOLI!!!

Hi guys,
I am looking for a little help with a couple of bits!!! I have only had my allotment a few months but it is going really well so far, I have planted my pumpkins and have two or three large ones already (the size of melons!!), will they last until October time, does this seem about right for now (sorry if it's is a really silly question but I am completely new to all of this!! Also I am trying to grow them into giant pumpkins for my children for halloween, I have looked on a couple of sites but to be honest I dont understand the technical terms!!! Something about male and female flowers (whats the difference and how do you know) and also what exactly are the vines and what do i need to break off (please put the reply into thick peoples terms!!!)

Also my brocoli has formed already and has now flowered, this I have been told means that it has died, did it grow to early because of the heat, I sowed the seeds at the correct time???

Please help!! Sorry for the lack of knowledge!!!