My Money, where's you go?

Hai friends, I wanna share you a little story, actually I call this "problem", yap my problem.

I live in Jambi city with my parents. And I get  my pocket money every month, and I have to manage my finance by my self, as can as me, and as enough as me. And , here, I was so wasteful, I often don't go to canteen a week before months are over. All of us know, we must eat to get more energy, actually I wanna go home , so that I can eat for free and save my money more, but my home too far from Jambi University and I'm sure you know our schedules are so tight. Finally, that be the one of factors why I'm so wasteful. Not only that, there are money wasted for travelling every weekend, photocopies document, charity, etc. So my dear friends, do you have any solution for my problem? Please tell me how to be smart to manage my finance and don't waste my money anymore.