You can set individual apps to download things like music, photos, videos, etc. to the card, but in that old of a version you can't set it download apps to the card.
You can move your photos, videos, music, to the SD card, using a file manager app or by connecting the phone to a computer via USB cord and moving the files over all at once that way. That will free up some space.
You can then uninstall (not just remove the icon) any apps that you don't use, and aren't locked on the phone by the manufacturer. Then lastly you can go into "Settings", then "Apps" and finally "All" then locate the apps you know have a lot of data taking up space on the phone that you don't need. In there tap the individual app that you want to clear data on (like clearing a browser on a computer) then tap "Clear Cache". Just make sure it isn't an app you want the data for, like oh the gallery or contacts.
OH and you can try installing an app like Clean Master that is free and can help you keep an eye on the space.