Because a site has to be found the URL has to be indexed in the major search-engines. There are expensive tools for this, but a first right step is to report your new site to Google:
Offcourse there is a special box where you have to type in a code. This is to prevent programms to send constantly URL's to the Google database that need indexing.
Google is a source for other search-engines as well. I'll come back to the theme search-engines soon. A first indexing gets into the system, and it might start to cause visitors that come tou your site because of specific words that you mention on your site.