I just wanna know if it will make it my default browser and get rid of my other ones or what
Sure you will be able to use your browsers: it's just another browser on your system. And - regardless of many others - it's installer does not set it as a default totally, so you are free to use it only the times you're launching it explicitly
Yes. You will have added an additional browser, but it will not remove or otherwise affect your current browsers in any way.
Yes, when you extract/install tor it installs into a separate directory, it will never ask to become your default browser.