Hello, I recently purchased a property and right across the street is what seems to be a vacant property in a developing neighborhood.

My investment goals include building a portfolio of rental properties, focusing on both single-family homes and multi-family units.

I understand there is also property management software that combines ACH payment capabilities with feature with basic book keeping features, perhaps work orders/repair requests, document(lease) archives, leasing/listing features? 

Do you own any properties yet?

Yes, they made me the property manager.

I currently have a property with a 4 unit on it.

Also as a sidenote I assume you are lending on non owner occupied homes - never lend on an owner occupied property.

By investing out-of-state, you can find properties with lower prices and higher rental yields.

I'm considering selling the unit instead of finding another tenant.

To illustrate:You inherit a property today that your relative/friend bought 10 years ago for 100k.