You invite search engines to visit your website.
When you submit your website URL to a search engine, you basically ask the search engine spiders to visit your website and to evaluate it. If the search engine spiders cannot find anything useful on your site, they won’t list your website. It doesn’t make sense to submit your website to search engines if you haven’t optimized it before.
Here’s where you can go to have your site added to:
Yahoo: https://siteexplorer.search.yahoo.com/ (you will need to register first)