I want to be a foreign language high school teacher in Texas, advice needed!

I would appreciate advice. I am originally from Switzerland and do not have a bachelor's degree. My education was done 30 years ago and I did a Matura in foreign languages. Back then, this was the higher degree than elementary or secondary teachers. However, it is not university. Because it doesn't transfer as a university degree to the United States, I had done many other jobs when I moved here (my last was sergeant, and lieutenant in the Texas prison system). However, I am fluent in multiple languages and tutor off and on, sometimes for free, and sometimes for money. My children are now grown and I decided to go back to university. I am studying sociology. I currently sub for the local high school and sometimes work as an instructional assistant for the sped classes. I love all of it! A nearby high school is currently looking for a French teacher, and I would love to get that job. But, here are my questions: I read that you can teach while getting your teaching degree, is that true? If so, does my sociology enrollment count or do I need to be enrolled in something else? Do I need to register at the Texas State Licensing Board already? I find the online information very confusing and not very helpful for foreigners. Would anyone be able to give me advice? I am willing to teach French in any way possible at the high school and I want to apply this weekend for this job. How can I demonstrate that I qualify and how can I legally qualify in Texas for this job?