Hello and thanks you for using Just Answer. You should file your 2007 Form 1120S and start to depreciate your purchases and building. If you did not have income for 2007 your losses for 2007 can offset any gains for 2008 or future years gains.
Depreciation begins at the point when property is "ready and available" for use in a trade or business, regardless of when the asset was purchased. The date it is placed in service is used to determine when the tax year depreciation begins. If the property was "read and available" for use in February 2008 that is the date you should use.