DIY dealing with rust

[praivo]

Hi,

I got a 2000 Yaris from my grandparents who bought a new car. The car was free but turned out to need a ton of repairs. New oil (+ filter) and a CV boot (already done), new carpet (this one has a hole in it), new shocks, new licence plate holder, new air filters, new tires... And then there's this: http://imgur.com/a/4da2K

I'm not surprised by the rust because my grandparents didn't really take care of the car simply ignored the rust. However, that means that I'm now the one who has to deal with it. And as a student who couldn't find a job for the holidays, I have very little money to spend on the car which means I probably won't be able to get this (as well as almost everything else) fixed properly for at least a month, if not longer.

Is there anything I could do now to prevent it from getting worse until I get the money for a proper fix?