This is a basic standard guide on uploading and installing a WordPress theme.
First step is to login into your ThemeForest account and access the downloads section https://themeforest.net/downloads . You’ll notice the Rey theme item and the green Download button. Click on it and then click on “Installable WordPress file only”.
After you downloaded this file, access your WordPress dashboard and go to Appearance > Themes and here, look for the Add new button.
In the next screen, click on Upload Theme and then Choose file and look for the zip archive you downloaded from ThemeForest. Finally, click on Install now.
After installation, click on Activate.
Right after you Activate the theme, you should be redirected to Rey’s built-in setup wizard.