This particular time will be a 6 month lease with a single tenant over that time. 

And if you want safety and surety, you will very likely not be getting much more than high single digits/low double digit returns.

If a large % of tenants are paying well after the 5th you have a problemTenant retention - This will vary wildly but something like for single family homes I'd want at least half of the folks staying over 3 years. 

Anyone have recommendations for a program(s) or other means to keep records for my new LLC and new investment property (a single family house)?   

Many investors start with single-family because it’s a great way to learn the ropes, build equity, and get comfortable with the process before scaling into multi-family.

Focus on having your leases, screening process, and communication systems ready before move-in so you feel confident and prepared.

The lack of communication is concerning to me.

You might find a single-family in a better area than a multi at the top end of your range, which could help with long-term appreciation and tenant quality.

Breaking out into silos where the owner deals with multiple SMEs vs a single point of contact. 

In many jurisdictions, if a property isn't legally habitable or lacks a required certificate, tenants may have grounds to withhold rent or even break the lease.That said, here are a few general steps you can consider:Open a line of communication – Ask the tenant to put their concerns in writing.