Share 'When and how should we start networks?'

Hi! I am a college student who has always wanted to travel abroad for working purposes. I was just wondering how should we go about networking or applying for jobs. I know I probably won't be able to work while I am still in college, but I was wondering how early we should contact employers about our interest, when is too early? If I know I can't work for another 3 summers do we wait until the ...