I think it depends on your schedule. I've always studied and worked at the same time and now I'm used to it, but it's not easy. You can get your bachelors and start teaching. That teaching experience will be an advantage to you, allowing you to reflect upon your Masters in a more deeper way. If you do it like this, make sure you'll be able to dedicate time to your masters. Otherwise, I'd get a bachelors and the masters and then start teaching.