The asset entry worksheet on in turbo tax is asking for a 'Date placed in service'. do i use the date that I originally purchased my rental

Your rental property is considered "placed in service" for tax purposes as of the date when it is ready and available for a specific use in that activity, which may be later than the date it was purchased. Even if you aren’t using the property, it is in service when it is ready and available for its specific use. It can be considered available if it is held out for rent at fair rental value for the area.

See IRS Publication 527 for more information.

See here for more information from TurboTax on rental property.