Visiting Houston and scared

We are visiting Houston with our kids in the summer. We live in a different country with strict gun laws. And every day I am reading of mass shootings in the US, especially Texas. We are visiting family but don't want to stay in the house the whole time. How is the situation there? Are there armed security in malls and stuff? Is there anything that you can do to increase your personal safety? Is it crazy to get bullet proof vests? I know I'm probably being paranoid but I'm reading how the US has two mass shootings a day and now with this Dallas story I'm just scared. (Also if you have suggestions of fun things to do in Houston in August with kids I'd love to hear them)