Installing a theme

okay here is what you have to do.
login to your admin area and then click on dashboard. Then go to appearance and click on it and then click on themes. Then you will be presented with options to upload. Since theme file is a zip file, upload it and click on install, then you can activate the theme.
Hope this helps.
And to prevent waiting for replies like this i suggest you to go through the codex or try to get a course for beginners on WordPress.

Cheers

I did pay for hosting through wordpress

this might be with wordpress.com – please contact them at https://en.support.wordpress.com/contact/

if you have a selfhosted site running wordpress.org, read https://codex.www.ads-software.com/Using_Themes
or
https://codex.www.ads-software.com/Getting_Started_with_WordPress