Converting Twenty Sixteen to Responsive

I am building my site using the Twenty Sixteen theme. My issue is that I cannot figure out how to get the whole site to resize when I change the browser window size or when it is viewed on a different device. I know I will probably have to use jQuery but I have not been able to find ANY tutorials to show me how to do it step by step. My site is just a few images and a nav bar but I haven’t been able to find a solution that gets them to resize. Please help!