Hi Jeffrey!
First, do you have enough storage on your device to download the app?
Second, are you currently on Wi-Fi and accessing the Google Play Store? Are you able to get to other sites or apps with the connection? Perhaps try toggling the Wi-Fi off and accessing the store. Or, try downloading a smaller app over data to see if it works.
Third, you could try clearing the cache for the play store and google play services. Go to the settings app > apps/application manager (make sure its set to all apps) > look for Google Play Services > you'll want to clear cache. Go back one to the application manager and find Google Play Store and clear the cache for that as well.
Fourth, a simple device reboot is always a nice resort last option