You can start with the link to the learn WordPress.com tutorial found at the bottom of your Admin page. You can also use the "support" link at the bottom of your Admin page to search there > getting more views and traffic. Then search the forums and you will find lots of relevant advice.
Here are 25 basic steps to take to increase traffic to your blog:
1. Structure a reader and search engine blog;
2. In blogging content is king create unique, high quality content so publish fresh content frequently;
3. Learn basic SEO so you can use keywords effectively and apply basic SEO to your headlines, blog and posts;
Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results.
4. Make your blog posts look professional;
5. Create at least 4-6 pillar posts and continue to create pillar posts;
Pillar posts are also referred to as flagship content. Pillar posts are comprehensive posts that offer great value to readers as the contents are timeless in nature. They define you as having authority in the niche you blog in.
6. Select and link to appropriate anchor text;
7. Leave meaningful comments on related blogs and encourage comments on your own blog;
8. Develop relationships with other bloggers so you can build a blog readers’ community around your own blog;
9. Support the blog centered communities on related blogs by commenting on them and promoting posts from them;
10. Link to authoritative sources in your posts;
11. Deep link to your earlier related posts in your new posts;
12. Assign appropriate categories and tag your posts with care;
13. Link to related authoritative blogs in your blogroll;
14. Provide RSS feeds for subscribers;
RSS (Rich Site Summary or really simple syndication) is a format for delivering regularly changing web content. Many news-related sites, weblogs and other online publishers syndicate their content as an RSS Feed to whoever wants it.
15. Having a well designed theme is important, evaluate your theme for effectiveness, and if required, create a new header, make improvements or replace your theme and reduce page loading time;
16. Avoid cluttering your blog with widgets that lack reader value and slow page loading time;
17. Buy your own domain and domain mapping;
18. Verify your blog with the three big search engines.
19. Get organized, use an online to do list by developing a blogging workflow;
20. Join social networks and social media sites like Facebook and use Twitter, Friendfeed and other Free RSS directories to promote your blog posts;
21. Promote your blog through social networks, online groups, and selected directories;
22. Develop a social media time management strategy and stick to it;
23. Submit your latest pillar article to a blog carnival;
24. Become a guest blogger on sites with higher page rank than your own site.
25. Create newsletters and/or ebooks for your subscribers.
Do note that if you have been told "build it and they will come" that's nonsense.