There are numerous ways to use filemaker go and sync data later on.
If you're just a single user though, you can just pass the .fmp12 file to and from your iPad using iTunes and you won't need to write any sync at all. Syncing is only needed when you have two files that need to sync data with eachother.
We would need more information about your solution and how you plan on hosting filemaker for the desktop if you wanted more recommendations.
Filemaker Go does not natively sync with filemaker pro. They can sync but it is up to the developer to create scripts to perform the syncing. There are also a few solutions available that will assist you with the syncing process. Another option is to store all of your data on FileMaker Server so syncing is not needed.