I have started a new work last week and at this rate I won’t earn enough to even pay for the room I’m renting.

I wanted to earn as much money as possible during summer because I need to buy a new PC for university but after the first week where I was in training and I got one 12h shift on Saturday and right now I don't even know what I'm supposed to do now. I've called to ask for some kind of schedule or something and they told me that I should not worry because they will find work for me, but it's already 2 days after I called and no one is telling me anything.