Once you purchase the theme from themeforest, you’ll be able to load 2 file type.
If you select to download all files and documentation ( the zip name will be themeforest-xxx-xxxxx.zip ), you have to extract it out ( to get themename-vxx_xx.zip file ) before installing it to wordpress system.
After you install the theme, there’ll be a list of suggested and recommended plugins at the top of the wordpress dashboard.
If you already hide it out, you can go to ‘Appearance > Install Plugins’ section instead too.