Now that you've got your beanstalks at home, don't forget to look after them properly. They're too big for the small cups we planted them in now so you need to move them into either a big pot or straight into the ground as soon as possible. They need to be somewhere sunny and don't forget to water them regularly too. In the next few days you should start to see black and white flowers opening up (like in the photos below) which will attract bees and other insects. Once the flowers have fallen off, your broad beans will start to grow. Hopefully by July, you'll have some big bean pods which you can pick and eat.
Try to measure your beanstalks twice a week to see how much they're growing.