Second home ... if you live in it for 2+ years then you can take the personal residence exclusion
First home ... if you live in it for 2 out of the last 5 years working back from the sale date then you can also take the personal residence exclusion if you wait 2 years from the second home's sale date. HOWEVER you will need to recapture the depreciation you MUST take on the home while it was a rental. Seek local professional guidance if you still have questions on this matter.
