If you already know how to create a new database or have already created one, skip to the next step. In most cases you should be able to create a database from your hosting's control panel. Either from a separate databases section, or from within phpMyAdmin.
While this step is optional in most cases, it is highly recommended you do this for security reasons. You should change default directory for your website content from root folder to public sub-folder. You should be able to do this from your hosting's control panel.
Download the app from CodeCanyon.
Double click the downloaded file.
Copy website.zip file to the root of your server (usually called www or public_html). Either via built-in file manager in your control panel or a 3rd party FTP application like FileZilla.
Extract the website.zip file. (Make sure files are extracted directly to root folder and not in website sub-folder)
After extracting website.zip file, the file structure should look like this:
Open your site url in the browser and follow on-screen instructions to complete the installation.