Headed to Texas for winter

I am on my way down to Mission, Texas, in the Valley, where I spend the winter. I've gone down to the same area for the last several years but I have never been a cyclist there, beyond riding my old comfort bike. I also never drove around much, spending most of my time in the neighboring state park. So, I don't know the area as well as I probably should. Any tips or warning about riding in Texas? Are there those horrible thorns that populate the western US and flatten tires? Any weird rules about riding the road?

I am a little nervous about doing long rides in the area because I am going to be by myself for most of the winter. I guess I will find the local taxi services and put their numbers in my phone. I also am thinking of getting a Garmin so I am less likely to get lost.