If my principal residence is an apartment in a condo complex, should I mark the box that asks if the residence is part of a multi-use or multi-family property?

I'm not sure what section of TurboTax you are referring to. However, if your assessed value is solely for my personal condo then you should probably NOT mark the box which asks if the residence is part of a multi-use or multi-family property because you will not have to split anything.