Our Grafted lime trees put a little production in year 2 and 3 but nothing noteworthy.  

That leads to frozen pipe, snapped trees, roof damage, etc.

Lots of trees .

If your sewer or drain backed up because a tree root clogged the pipe outside the foundation.

We prepaid the fees as part of the initial investment, which we were told would be enough until the trees started fruiting. 

Ideally I'd like to invest somewhere like the Catskill Mountains or Joshua Tree (based on my connections to the area).

That is a good solution.

I have a mix of residential and commercial properties. I'd like to be able to manage both in a single software. Right now, I'm just using Google spreadsheets and it's getting tiresome.... I've never used any software ...

What’s the solution? 

@David Proffitt for a cheap solution, recommend getting a GoogleVoice number.You can access it from a computer, which makes text-typing more efficient.You can also train your tenants to only text you, which will then allow you to have a record of every conversation.