I'm Worried About A Swimming Test, Tomorrow?

Alright, so my class is going to a day camp tomorrow as an end-of-the-year kind of thing. No homework, no classes, no education! So, I originally thought it was going to be fun. Then, today I found out that in order to be able to swim in the deep end, there's going to be a test that is a race and being able to tread water for 30 seconds. I can swim, I'm just not...thereee....you know what I mean? So, all my friends are going to be able to swim in the deep end and I'm going to be the only one in the shallow end! I mean, I haven't taken the test (it's tomorrow, DUH! lol:P), but I know that I'm not going to pass. Of course, maybe I could pass if I had suggestions on how to swin better! Do any of you have any tips or tricks to swim better? I have minor asthma, so I get worn out easily, so keep that in mind.