Some ISPs will provide you one. Currently, Netscape Navigator is the most popular. It is available free for use in educational institutions. Microsoft's Internet Explorer is also popular. It is free to everyone.
Most web browsers are very similar.
Here, we'll describe some basic features of Netscape Navigator, the most popular browser. Most of the information applies to any browser. See the manual for the browser you are using for additional details. First you have a window to display the current page. It is just like any other Mac or Windows screen.