Trouble installing apps

Hello, I recently bought an iPod touch 5 and have been downloading games and apps for about three days now, but i'm having a problem. When installing a few of my games, they either quit installing and slowly start all over, or I get an error message saying that I can't install the game right now. One of them I purchased for $6.99, and I'm worried that I wasted money because I can't install it. i'm pretty sure that the games I'm trying to download aren't iPad only. I know I seem a bit low-tech, but this is my first "smartpod" if you understand what I mean. How do I fix this problem?

Details: the apps are dark with the white installing circle on them, and under the app badge is the word "installing". The circle usually finishes around halfway when it suddenly turns all dark again with the app's name under it. If I click on the app, the name changes back into "installing". It then repeats the cycle. This happened many times with some apps, and I'm not sure what to do.