You can learn from this how to install correctly a theme and check if your server has the necessary requirements to work with this theme.
IF YOU ARE A BEGINNER IN WORDPRESS, START HERE:
We recommend you dedicate enough time in learning the basics about this Content Management System
Install WordPress (codex), https://codex.wordpress.org/Installing_WordPress
First Steps with WordPress, link: http://codex.wordpress.org/First_Steps_With_WordPress
More about themes in WordPress, link : http://codex.wordpress.org/Templates
New FAQ about WordPress, link: http://codex.wordpress.org/FAQ_New_To_WordPress
HOW TO INSTALL WORDPRESS
You have to take into consideration that your package of hosting must support WordPress. That means it should have database MySQL and PHP support, as weel as an FTP access to the site. Please consider that some hosting servers, especially the cheapest ones, keep a limit in PHP and others. If you are having problems of performance with WordPress you may consider migrating to other hosting with more capacity (Better hosting).
In youtube there are lot of video where they explain in a simple and easy way how to install wordpress. We know that can be of much help for you.