Community property adjustments are based upon the type of property owned. For example, if you and your spouse acquired property together during marriage or is property that is not easily considered as being separate, then that specific property is treated as being community property. If it does not fall under this general overview, it is probably separate community property. Page 3 and page 4 of IRS Publication 555 provide more specifics on what would be considered separate property.
In regards to preparing your tax return, when you file as married filing separately, you will need to include 50% of any community property income and deductions as well as 100% of your separately owned property income and deductions.
Please see this link for more details to guide you as you enter this information into TurboTax.