Filemaker Go does not have build in syncing. You can design your own or purchase 3rd party software such as GoZync by seedcode.
You may want to check out the Auto-Restore Login page 8 of Go Technical Brief.
Thank you for your post.
The answer by "S Chamblee" is correct (Thank you).
I know of one customer with a similar scenario that was adding (not updating) data to a hosted file. The customer would add the data to a temporary table, and then a script was called to open the remote file. If successful, a script was run on the hosted file to import the data from the local file, and then the contents of the temporary table were deleted. This may or may not apply in your situation, but I thought I should mention it.