I love this house and don’t want to lose it, I would like to add houses in the long term and build a portfolio. 

The house isn't in a flood zone.

I asked PM to send a bigger cleaning crew vs 1 person as the house is 2600 and needed a good cleaning.

Hello Everyone,I really want to learn how to rent my house and aquire another house to rent and so on.

I don't think listing with an agent will work since I am not looking to sell to the general public, I do get these yellow post cards and letters from "CASH FOR YOUR HOUSE NOW" but I believe those are not investors buyers but more bird-dogs looking to get it on a contract to reassign at closing. 

I found a house in Atlanta that comes out to an IRR around 11% when I run the numbers, is that good or should I look for better?

Yes you could buy 1 house cash for $500,000, or you could buy $2,500,000 in real estate with 20% down.When the market appreciates 20%, one would yield you $100,000 while the other would yield you $500,000.This also doesn't calculate the increased cash on cash return you will get with increased rents across all of your properties rather than 1. 

House hacking has been my approach here, otherwise the numbers don't really work.

What are the requirements for an owner to hold an open house in Texas?  

Real estate investing is like exploring a new world, and it's awesome that you're diving into strategies like BRRRR and house hacking.