If I bought a home in Oct and moved out of first home, and then did not rent the first home till next year, then do I consider the first home as rental property or not?

[Opus 17 · Accepted solution]

You list it as rental property beginning from the date when you place it in service; when you make it available for renting.  If you advertised it as available in November or December then it is a rental property as of then even if you didn't actually find a tenant until the next year.  But if you only made it available in the new year, that is when it would be listed for rental.