Select Offline Files and press Sync
Let the sync run.
- If this is your first sync on this machine it has to copy all your Home Directory files from SU's file servers to this machine. This can be as much as 100 GB and can take more than an hour.
- All future sync's copy only the files you've changed. This is much quicker.
- Wired network connections can be ~20x faster than WiFi network connections.
When it's done the Last sync on date should be in the recent past. If there are conflicts go ahead and try to resolve them. Usually the newer file is the one you want to keep. If you're in doubt save them both.