If by "things" you mean pictures, music, movies, and documents:
Using your favorite file browser app,
- create a folder on the SD card to hold the files
- select the files you want to move
- COPY these files to the SD card
Restart the phone to flush the file buffers on the SD card.
Using the file browser app, and the viewer/player app for the files, verify that the files were correctly copied.
Using the file browser app, delete the copied files from the internal storage.
Repeat as needed.
Apps should stay on the internal storage. In most cases, you cannot move the anyway.