Now that you have a blog. Start blogging.
Click the link "Start blogging!" and create your posts. You can post about anything you want/you are good at. Blog regularly, don't be upset if no one ever visits your blog. Just create blog by your own interest. Visitors will come. Trust me.
At the starting of your blog visitors don't know about the blog you are creating. Your blog not even listed in search engines. Updating blog regularly is the best way to be listed in search engines. The more you create, the more search engines send bots to visit your blog and update logs about your blog.
To attract visitors, your blog should contain some unique posts. It is a good practice to blog about something you are good at. That will pull more visitors to your blog.