You need to tell the individual app that creates and/or downloads the items (not apps) to use the card as the place to save them. So in say your browser, you would need to go into the browser app "Settings" and change the download location to the card. The same goes for the camera, or other such apps.
Now, if the apps you have don't have that option in their settings, you would need to obtain ones that do. You may also want to check the phones main "Settings" to see if there is an option for saving to the card.
For items already on the phone you want to move, you would need to either use a file manager app on the phone, or connect the phone to a computer via USB cord and move all the files over to an empty folder on the computer, then...