Howdy rball5. I'm just North of Dallas and just a bit outside of Plano.
The key as stated earlier is decide when you are going to ride and stick to it. Don't get caught up in the distance or speed, those things will take care of themselves. Just ride what you can and remeber it's further than not riding. Running yourself into the ground and setting new personal best for levels of discomfort will discourage you if you push too hard early on.
Don't worry, after a while you will intentionally put yourself in the pain cave just to see how long you can take it
Maybe a better way to put it is after a while you will enjoy testing your limits
I suppose being so close to Austin you are a McBevo fan. It's OK, we all have our imperfections
Gig'em!