As a junior is it bad that I don't know exactly what I want to be?

It's not "bad". In fact, it's quite normal. That's why CareerVillage exists, in fact. But having no idea what you want to do with your future is not doing you any favors either. There comes a time where being unable to pick something and commit to it for a period of time can be a great burden. So while you needn't become stressed by it, I recommend that you use this as an opportunity to start getting serious about exploring the world and the options available to you. Be aggressive about trying out new things. Keep a list of industries you think are neat and career fields you are interested in.

When my grandfather was young, he had to pick a career field and know that he would stick with it for his whole life. That's no longer the case. You will in all likelihood change careers several times over your lifetime. So don't worry about closing doors. You can always pivot later on. But in the short term, you can only do one thing at a time, and you should devote yourself to it fully for at least a couple of years.

As for college: it's okay if you change your major in college, but I wouldn't recommend changing it more than 1 or 2 times total. I changed it three times, and that set me back in the competition.