To start with the move, you’ll first need a domain and a hosting plan. If you already have a domain with WordPress.com you can refer to there guide on updating your nameservers to point to another host.
Make sure that you are already signed into your WordPress.com account. Go to your blog’s dashboard. On the left-hand column, you will need to click on the WP Admin link to open your blog’s admin area.
In the admin area click on Tools » Export.
Clicking on the Export tool will take you to a new page where you can select to export your content and/or media library.
You will be sent a download link once your export was successful.
You will head to the exact same spots as in step one but instead of selecting Tools » Export you will need to go to Admin »Tools » Import.
You will need to install the WordPress importer if it not already installed and then select the downloaded files from step 1 and then import your data.