Before you can vamp up your site with themes, you need to install and activate them in your WordPress admin. These are the basic steps for most themes:
1. Log in to your WordPress admin page, then go to Appearance and select Themes.
2. To add a theme, click Add New. From this page, you have two ways to add a new theme. If you know the name of the theme you want, search for it in the Theme directory. If you don’t know your preferred theme’s name, use the Feature Filter to hone down your selection, check any tags and click Apply Filter for a screen filled with themes that meet your search criteria.
3. To unlock a themes options, hover over it; you can either choose Preview to see a demo of the theme or install it by clicking the Install button once you're ready. Once installed, click the Activate link.
4. You're all done, now preview your site to see how it looks.
We recommend reading through any instructions that come with your chosen theme regarding installation. Some themes will require more steps than others, going beyond the basic steps covered here. Follow the instructions provided, and if you run into any problems, contact the theme’s author for help.