Do I have to set up Apache to use Subversion?

The short answer is no. The long answer: if you just want to access a repository, then you only need to build a Subversion client. If you want to host a networked repository, then you need to set up either Apache2 or an "svnserve".

For more details about setting up a network accessible Subversion server, see chapter 6 in the Subversion book.