How do I become a microbiologist? Is the career market for them impossible to find jobs like other STEM majors?
The hard aspect to finding a job is that there's no single "microbiologist job." The skill set fits into a variety of fields and careers. You could go into industrial research, med/pharma corporations, food and beverage industries, public health, hospital labs, etc. You have to be tenacious in finding any and every little nook and cranny in which you could fit. I know a microbio major who ended up finding a job at a cosmetics company of all places, but it turned out to be a wonderful score.
Take the major, try to get into an accelerated program (5 year MSc, for example) and network as much as possible. Get in close with people in your department and join any societies and organizations which you can.