Manage theme in Wordpress first of all you log into the Wordpress admin dashboard. When you are start development in Wordpress by default active theme Wordpress default theme. But you can change it install and active any premium theme. You can see the available Wordpress theme preview by clicking the preview link who show under the thumbnail. If you want change the Wordpress default theme.
First step: You can go Wordpress appearance menu and click on themes in sub menu. You show Wordpress by default theme and available themes
Second Step: If you want active any premium theme first of all download themes from theme website and click the button install theme then click the upload button and search them from your computer and click the button install show three options live preview active theme and back you click on the active theme link.
ow your theme successfully install and active.If your Wordpress website has many available themes you can search easily theme through the search bar. Any theme who you want search you enter theme name in the search bar.You can delete any theme click the button on delete