How do I get <, > and & to show up in a web page?

You can use HTML "entity escapes." for this.

You can write < as &lt;, > as &gt;, and & itself as &amp;. These special "escape" sequences are recognized by all web browsers.

There are other HTML entities which can be used to represent characters not found all keyboards which are nevertheless common, like the © copyright symbol. The escape for copyright is: &copy;. For a detailed guide to the "entities" available in HTML, see the
w3schools web site http://www.w3schools.com/tags/ref_entities.asp.