Purchasing more than one property a year

[Allison Jane]

I recently purchased a multi unit in San Diego, CA in August 2017. This is my primary residence, but I rent out the other unit at the property. I would like to purchase another rental property within a few months out of state(looking at Charlotte NC, Raleigh NC, Tampa FL). What are the constraints of purchasing a rental property within a year of primary residence purchase? How difficult is it to be approved for an additional loan in the same year?